find f(-1) given that f(x)={(3x^2-1), (-1/4), (3x+2), (x is less than or equal to 4), (-4

Question

find f(-1) given that f(x)={(3x^2-1), (-1/4), (3x+2), (x is less than or equal to 4), (-4<x and x<2), (3x+2), (2 is less than or equal to x)}

(it's supposed to be a matrix)

clara1223 · Answer

Please help! I am overwhelmed with the amount of questions on this review that I don't know. I could use as much help as you can give.

dumbcow · Answer

ok this is called a piecewise function, the function changes for different x values.

match the given x value with correct domain, then use that function to input the x-value

f(-1)  ----> -1 is between -4 and 2, so you would use f(x) = -1/4

dumbcow · Answer

another example:
f(3) ----> 3 is greater than 2, so use f(x) = 3x+2
plug in x=3 ----> 3(3)+2 = 11
f(3) = 11

clara1223 · Answer

@dumbcow where did you get -1/4 from the fact that it is between -4 and 2?

dumbcow · Answer

because its given in the "matrix" 

x< -4 ,   3x^2 -1
-4<x<2,   -1/4     <-----
x>2  ,     3x+2

clara1223 · Answer

@dumbcow thank you so much!

dumbcow · Answer

yw :)