Question

PLEASE HELP!!
Solve:
1. cos(arcsin(4/5))= ??
2. tan(arccos(4/5))= ??
3. cos(arctan(3))= ??
Note: Give exact answers!!

Answer 1

Let's first understand what this kind of question means.
I will do the 3rd one

cos(arctan(3))

arctan(3/1) means the angle Ø so that tanØ = 3/1
so draw a right angles triangle with angle Ø, opposite as 3 and adjacent as 1, ( remember tanØ = opp/adj )
By Pythagoras, the hypotenuse is √10

so cos(arctan(3))
= cos Ø
= 1/√10

Do the first 2 the same way.

Answer 2

I got them :). Thank you so much for explaining it really well, my textbook doesn't explain well at all, that's why I was struggling!! Thank you once again!!

Answer 3

You are welcome,
90% of success in math is understanding it