Question

please help me with this trig.. sinu=3/5 and sinv=4/5, evaluate sin(u-v) and tan(u+v)

Answer 1

Firstly you should calculate cos(u) and cos(v).

Do you know how you will calculate these?

Answer 2

no i do not

Answer 3

See, we have an identity which says:
\[\sin^2(x) + \cos^2(x) = 1\]

Here let us find out the value of cos(x).
\[\cos^2(x) = 1- \sin^2(x)\]
\[\implies \cos(x) = \sqrt{1 - \sin^2(x)}\]

Getting this much?

Answer 4

oh ok i can do that, then do i use sin(u-v)=sinucosv-cosusinv?

Answer 5

Yep...

Answer 6

Firstly find cos(u) and cos(v) by using the formula I wrote above..

Then use that formula you wrote..

Answer 7

thank you very much friend, you're the best

Answer 8

You are welcome dear..

And I can be better but I am not the best..