Question

cos[tan^-1(-1) + cos^-1 (-4/5)
How would I find the exact value of this one?

Will FAN and MEDAL

Answer 1

1.5 Remember ^-1 is the inverse arc function, and not the inverse (not 1/x).

Answer 2

I made a mistake, the answer is 3.2

Answer 3

How'd you get that? All I have is that tan inverse is -pi/4

Answer 4

Did you leave out a bracket?

Answer 5

It looks like the final answer is the cosine of an angle which can only be less than or equal to one

Answer 6

There's a bracket at the end sorry @alekos

Answer 7

See if you get -0.1414214

Answer 8

how would I get cos inverse (-4/5) and is cos inverse -pi/4 .. 3pi/4

Answer 9

Use the arc cos function.

Answer 10

Whats the function

Answer 11

Are you using a calculator or other software?

Answer 12

I'm not allowed to use a calculator

Answer 13

Start from inside out to find values if each trigo inverse. Use triangle way to find exact values :)