Prove the following trig identities starting with the left side.
1) sin^2x + cos^2x = 1
2) (cosx - sinx)^2 + (cosx + sinx)^2 = 2
3) cotx + tanx = secx*cscx
Thank you for any help!
Prove the following trig identities starting with the left side.
1) sin^2x + cos^2x = 1
2) (cosx - sinx)^2 + (cosx + sinx)^2 = 2
3) cotx + tanx = secx*cscx
Thank you for any help!
1. This seems very weird, it's pretty much the basic proof.
Therefore if we square both:
Adding them:
By the definition of a right angled triangle and using Pythagoras the right side cancels to 1.
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2. Expand to give:
Remember what is equal to
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3. Rewrite in terms of sin and cos:
Give them the same denominator by cross multiplying
and cancel to give the rhs