If f(x) = sqrt(25-x^2)f(x)=25x2, what is the value of f(3)f(3)?

1 Answer
Jan 29, 2016

4 :)

Explanation:

since f(3) = sqrt(25 - x^2)f(3)=25x2,

we subtitute the value of x for 3 since f(3)
f(3) = sqrt(25 - 3^2)f(3)=2532

then evaluate the terms inside the radical sign (square root)
f(3) = sqrt(25 - 9)f(3)=259
f(3) = sqrt(16)f(3)=16

then finalize the answer, since 4*4 = 1644=16, the square root of 1616 is 4, hence the answer is:
f(3) = 4f(3)=4