# Trigonometry

Trigonometry equalities, inequalities and expressions - sin, cos, tan, cot

### Trigonometry

Show that the equation 3sin^(2)θ-2cos^(2)θ=1
can be written as 5sin^(2)θ=3
Guest

### Re: Trigonometry

sin2t + cos2t = 1
so
cos2t = 1 - sin2t

Can you write the rest?

Math Tutor

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Joined: Sun Oct 09, 2005 11:37 am
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sinx+cosx=1
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### Re: Trigonometry

sin²t + cos²t = 1

leesajohnson

Posts: 208
Joined: Thu Dec 31, 2015 7:11 am
Location: London
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### Re: Trigonometry

You need to do the sum........not just write out the trig. identity.....

Show that the equation 3sin^2t-2cos^2t=1
can be written as 5sin^2t=3

Cos^2t+Sin^2t=1 ....>>...Cos^2t=1-Sin^2t

So ... 2cos^2t = 2(1-Sin^2t)

and ... 3sin^2t-2cos^2t = 1 ...same as... 3sin^2t-2+2Sin^2t = 1 ...same as... 5Sin^2t = 3

...................................
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