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1. Determine whether the relation is a function. {(-2, -7), (3, -5), (6, -4), (9, -6), (10, -1)} A relation between x-elements and y-elements in which a given input produces exactly one output value always is called function. To check if a relation is function, given set of points, we need to check if any x- elements occur more than once. If any x-element is repeated, it isn’t a function. In this example, no x-values are repeated. Hence it is a function. 2. Find the slope of the line that goes through the given points. (-3, -7), (9, -7) (-3, -7) is the first point. So, x1=-3 and y1=-7. Similarly, (9, -7) is the second point . So x2=9 and y2=-7. Slope: m= change in y = y 2 -y 1 change in x x 2 -x 1 Hence, = −7−(−7) 9−(−3) = −7+7 9+3 = 0 12 =0 3. Find the slope of the line that goes through the given points. (-8, 8), (-5, 2) (-8, 8) is the first point. So, x1=-8 and y1=8. Similarly, (-5, 2) is the second point . So x2=-5 and y2=2. Slope: m= change in y = y 2 -y 1 change in x x 2 -x 1 Hence, = 2−8 −5−(−8) = −6 −5+8 = −6 3 = −2

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  • 1. Determine whether the relation is a function.

    {(-2, -7), (3, -5), (6, -4), (9, -6), (10, -1)}

    A relation between x-elements and y-elements in which a given input produces

    exactly one output value always is called function.

    To check if a relation is function, given set of points, we need to check if any x-

    elements occur more than once. If any x-element is repeated, it isnt a function.

    In this example, no x-values are repeated. Hence it is a function.

    2. Find the slope of the line that goes through the given points.

    (-3, -7), (9, -7)

    (-3, -7) is the first point. So, x1=-3 and y1=-7.

    Similarly, (9, -7) is the second point . So x2=9 and y2=-7.

    Slope: m= change in y = y2-y1

    change in x x2-x1

    Hence, =7(7)

    9(3)=

    7+7

    9+3=

    0

    12= 0

    3. Find the slope of the line that goes through the given points.

    (-8, 8), (-5, 2)

    (-8, 8) is the first point. So, x1=-8 and y1=8.

    Similarly, (-5, 2) is the second point . So x2=-5 and y2=2.

    Slope: m= change in y = y2-y1

    change in x x2-x1

    Hence, =28

    5(8)=

    6

    5+8=

    6

    3= 2

  • 4. Determine whether the relation is a function.

    {(1, -3), (1, 1), (6, -8), (9, -3), (11, -3)}

    A relation between x-elements and y-elements in which a given input produces

    exactly one output value always is called function.

    To check if a relation is function, given set of points, we need to check if any x-

    elements occur more than once. If any x-element is repeated, it isnt a function.

    In this example, the x-value 1 is repeated. Hence it is not a function.

    5. Find the slope of the line that goes through the given points.

    (-1, 4), (5, 4)

    (-1, 4) is the first point. So, x1=-1 and y1=4.

    Similarly, (5, 4) is the second point . So x2=5 and y2=4.

    Slope: m= change in y = y2-y1

    change in x x2-x1

    Hence, =44

    5(1)=

    0

    5+1=

    0

    6= 0

    6. Determine whether the relation is a function.

    {(-6, -9), (-2, 1), (1, -1), (7, -7)}

    In this example, no x-values are repeated. Hence it is a function.

    7. Evaluate the function at the given value of the independent variable and

    simplify.

    f(x) = 4x2 + 5x - 6; f(x - 1)

    f(x) = 4x2 + 5x 6

    To find f(x-1), we substitute x = x - 1

    f(x-1) = 4(x-1)^2 + 5(x-1) 6

  • f(x-1) = 4[x^2-2x+1] + 5x-5 6 f(x-1) = 4x^2 - 8x + 4 +5x 5 -6 f(x-1) = 4x^2 - 3x - 7

    8. Determine whether the equation defines y as a function of x.

    x = y2

    To check if the function x=y^2 defines y as a function of x, we solve the equation

    for y. If more than one solution is obtained, then y is not a function of x

    x=y^2

    y^2=x

    y=

    y=+ or y=- Hence, The equation y2 = x does NOT define y as a function of x because

    when we solve for y we must apply the square root property, which will

    leave us with TWO solutions for y.

    9. Evaluate the function at the given value of the independent variable and

    simplify.

    f(x) = x2 - 1; f(x - 2)

    f(x)= x^2-1

    f(x-2) = (x-2)^2-1 f(x-2) = (x^2-4x+4) - 1 f(x-2) = x^2 - 4x + 4 - 1 f(x-2) = x^2-4x+3

    10. Determine whether the relation is a function.

    {(-5, -4), (-2, 9), (-1, -2), (-1, 7)}

    In this example, the x-value -1 is repeated. Hence it is not a function.

  • 11. Determine whether the equation defines y as a function of x.

    x + y = 9

    To check if the function x=y^2 defines y as a function of x, we solve the equation

    for y.

    x + y = 9

    x + y -x = 9 x y = 9 - x

    Hence, as each value of x has unique corresponding y value, the equation

    defines y as function of x.

    12. Determine whether the relation is a function.

    {(-7, -1), (-7, 2), (-1, 8), (3, 3), (10, -7)}

    In this example, the x-value -7 is repeated. Hence it is not a function.

    13. Determine whether the equation defines y as a function of x.

    x2 + y2 = 1

    To check if the function x=y^2 defines y as a function of x, we solve the equation

    for y. If more than one solution is obtained, then y is not a function of x

    X^2 + y^2 = 1

    y^2 = 1 x^2

    y=1 ^2

    y=+1 ^2 or y=- 1 ^2

    Hence, The equation y2 = x does NOT define y as a function of x because when we solve for y we must apply the square root property, which will

    leave us with TWO solutions for y.

  • 14. Find the slope of the line that goes through the given points.

    (-2, -6), (-9, -17)

    (-2, -6) is the first point. So, x1=-2 and y1=-6.

    Similarly, (-9, -17) is the second point . So x2=-9 and y2=-17.

    Slope: m= change in y = y2-y1

    change in x x2-x1

    Hence, =17(6)

    9(2)=

    17+6

    9+2=

    11

    7= 11/7

    15. Find the slope of the line that goes through the given points.

    (-7, 6), (-7, -9)

    (-7, 6) is the first point. So, x1=-7 and y1=6.

    Similarly, (-7, -9) is the second point . So x2=-7 and y2=-9.

    Slope: m= change in y = y2-y1

    change in x x2-x1

    Hence, =96

    7(7)=

    15

    0=

    The line is parallel to Y-axis.

    16. Find the slope of the line that goes through the given points.

    (3, -5), (-9, -8)

    (3, -5) is the first point. So, x1=3 and y1=-5.

    Similarly, (-9, -8) is the second point . So x2=-9 and y2=-8.

    Slope: m= change in y = y2-y1

    change in x x2-x1

    Hence, =8(5)

    93=

    8+5

    12=

    3

    12=

    1

    4

  • 17. Use the given conditions to write an equation for the line in point-slope

    form.

    Slope = 6/7, passing through (8, 7)

    The point slop form is

    y-y1=m(x-x1)

    Here, given m=6/7 and (x1,y1)=(8,7)

    Hence, the equation in point slop form is

    y - 7 = 6

    7(x - 8).

    18. Use the given conditions to write an equation for the line in point-slope

    form.

    Slope = 4, passing through (-3, 7)

    The point slop form is

    y-y1=m(x-x1)

    Here, given m=4 and (x1,y1)=(-3,7)

    Hence, the equation in point slop form is

    y - 7 = 4(x (-3))

    y - 7=4(x+3)

    19. Evaluate the function at the given value of the independent variable and

    simplify.

    f(x) = -3x - 8; f(-2)

    f(x) = - 3x - 8

    To find f(-2), we substitute x= - 2

    f(-2) = -3*(-2) - 8

    f(-2) = 6 8 f(-2) = -2