How would I prove the following.

arcsin(4/5)+arctan(3/4)=pi/2

Any help is appreciated.

Printable View

- Dec 13th 2012, 06:21 PMhomeylova223Proving trig equation?
How would I prove the following.

arcsin(4/5)+arctan(3/4)=pi/2

Any help is appreciated. - Dec 13th 2012, 06:36 PMMarkFLRe: Proving trig equation?
You could draw a 3-4-5 right triangle and:

a) find that

b) find that

Then use the fact that the sum of two complementary inverse trig functions having the same argument is always . - Dec 13th 2012, 06:50 PMhomeylova223Re: Proving trig equation?
I see why is it that the sum of two complementary inverse trig functions is pi/2?

- Dec 13th 2012, 06:54 PMMarkFLRe: Proving trig equation?
Because by definition, they represent complementary angles.

- Dec 13th 2012, 07:01 PMhomeylova223Re: Proving trig equation?
I see thanks.

I have a similar question.

It is

arcsin(3/5)+arcsin(15/17)=(-13/85)

How would I explain this problem. I know sin(a+b)=sinacosb+cosasinb.

But I am not sure what to do. - Dec 13th 2012, 07:18 PMMarkFLRe: Proving trig equation?
What you mean is:

There are two ways we could proceed:

a) Take the sine of both sides:

b) Take the cosine of both sides:

See if you can do this. Post your working, please.