Find the exact value if any of the following composite funct

Find the exact value, if any, of the following composite function. Do not use a calculator cos (cos^-1 2.1) Select the correct choice below and, if necessary, fill in the answer box within your choice. cos (cos^-1 2.1) = (Simplify your answer) Type an exact answer, using pi as needed. Use integers or fractions for any numbers in the expression.) It is not defined.

Solution

he equation for cosine is cos(A)=Adjacent / Hypotenuse. The inside trig function is arccos(2), which means cos(A)=2. Comparing cos(A)=Adjacent / Hypotenuse with cos(A)=2, find Adjacent=2 and Hypotenuse=1. Then, using the pythagorean theorem, find Opposite=i3.

Adjacent=2

Opposite=i3

Hypotenuse=1

Substitute in the known variables for the equation cos(A)=Adjacent / Hypotenuse

cos(A)=2/1

Simplify.

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