Question

Evaluate tan (inverse cosine of 2/3).

a. square root of 5 divided by 2
b. square root of 5 divided by 3
c. square root of 5 divided by 5

I have a feeling that the answer would be a but what i am confused about is how do we figure out what the value is for inverse cosine of 2/3.

Answer 1

draw the triangle with sides side2 and hypotensue 3. That makes the opposite side sqrt5.

Then the tan of that angle is (sqrt5)/2

Answer 2

Thank you so much! I get it now!!!