Question

Simplify
(cos5theta-cos theta)/ (sin5theta-sin theta)
@mathmate

Answer 1

= cos5 cos - sin5 sin
=..

Answer 2

@eric_d
Are the "5"s exponents or multiplicators?

Answer 3

\[\cos 5 \theta ...\]

Answer 4

shld be multiplication

Answer 5

the given answer is -tan 3 theta

Answer 6

@eric do u know tht cosA - cosB = 2sin[(A+B)/2]*sin[(B-A)/2]

Answer 7

I got to go soon, but hope these identities help you:
\(cos(5t)=5*cos(t)sin^4(t)-10cos^3(t)sin^2(t)+cos^5(t)\)
\(sin(5t)=sin^5(t)-10cos^2(t)sin^3(t)+5cos^4(t)sin(t)\)
and
\(\large -tan(3t)=\frac{tan^3(t)-3tan(t)}{1-3tan^2(t)}\)

Answer 8

Yes, I do.
This set of identities is very useful.

Answer 9

Will talk later!

Answer 10

sin A - sinB = 2cos[(A+B)/2]*sin[(A-B)/2]

Answer 11

Thanks.. @mathmate