McGraw Hill Integrated II, 2012
MH
McGraw Hill Integrated II, 2012 View details
2. Surface Areas of Prisms and Cylinders
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Exercise 48 Page 821

Substitute the value for the variable.

f(-2)=9

Practice makes perfect
To evaluate a function for a certain value of x, we need to substitute the given value for every instance of x. Let's do this for the given function when x=- 2.
f(x)=x^3 + 4x^2 -2x - 3
f( -2)=( -2)^3 +4( -2)^2 - 2( -2)-3
f(-2)= -8 +4(-2)^2 - 2(-2)-3
f(-2)=-8 +4(4) - 2(-2)-3
f(-2)=-8 + 16 - 2(-2)-3
f(-2)=-8 + 16 - (-4)-3
f(-2)=-8 + 16 +4 -3
f(-2)=9
When x=-2, the value of the function is 9.