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solve the function

(fx)=3√x+1    find f(-9)

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the answer is either 9i +1 or 3x(81/2 )i

yes the 1 is under the radical....and the "3" is a cube root...it just doesnt look like it here.so its the cube root of x+1.

Moriah, next time use parentheses for obvious reading :)

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3 Answers

Cube root means: what number multiplied by itself 3 times, will give you the number under the radical.

In this case, you start with the cube root of (-8) after you plug in (-9) into the original equation.

The cube root of (-8) = -2

To check your answer: multiply -2 times itself 3 times.

(-2) (-2) = 4

4 (-2) = -8

f(-9) = ^3√(-9 +1) = ^3√(-8) = -2

the answer is either 9i +1 or 3x(81/2 )i