grade 11 math
posted by Cindy on .
if f(x)= (x4)(x=3) determine the x intercept of the funtion if
y= 2f(x)...
i just don't know if the 2 affects the answer because that only affects the y co ordinates. in the book it says 4,3 but i don't know why.
if this is true if the they were asking me to find the y interpct of the function what do i do. THANKS!!!!

You have a typo, but looking at their answers of 4, and 3 , I know it must have been
f(x) = (x4)(x+3)
so we want
y = 2(x4)(x+3)
for the xintercepts, y = 0
then
2(x4)(x+3) = 0
x4 =0 or x+3 = 0
x = 4 or x = 3 , as stated.
for yintercept let x = 0, real easy ....
y = 2(04)(0+3) = 24