Ask a New Question

Asked by Kewal

If A + B + C = 180°, Prove that
Cos²A + Cos²B - Cos²C = 1 – 2sinAsinBcosC
13 years ago

Answers

Answered by Dorien
I've got the same problem! please help
11 years ago
There are no AI answers yet. The ability to request AI answers is coming soon!

Submit Your Answer


We prioritize human answers over AI answers.

If you are human, and you can answer this question, please submit your answer.

Related Questions

A) How do you prove that if 0(<or=)x(<or=)10, then 0(<or=)sqrt(x+1)(<or=)10? B) So once that is f... Prove that the sum of the vectors from the vertices to the centre of a regular octogon is a zero... Prove that sin(A+B+C+)cos(B+C)-cos(A+B+C)sin(B+C)=sinA How to prove this (e^(2^-1 i3pi) - e^-(2^-1 i3pi))/(2i) = -1 if you could show me this that wo... Prove 3+4+5+...+(n+2) = [n(n+5)]/2 for n>4 Do the first step in a proof by induction. Prove that 20^22 - 17^22 + 4^33 - 1 is divisible by 174. 1. Prove that (f(x+h)-f(x-h))/2=f'(x) 2. Prove that any parabola sastifies the equation (f(x+h)-f(x... Prove that a^3 ≡ a (mod 3) for every positive integer a. What I did: Assume a^3 ≡ a (mod 3) is... prove that 1+1/4+.........+1/n^2<2-1/n Prove that x=2 in 3^x + 4^x = 5^x?
Submit Your Answer

Question

If A + B + C = 180°, Prove that
Cos²A + Cos²B - Cos²C = 1 – 2sinAsinBcosC

Ask a New Question
Archives Contact Us Privacy Policy Terms of Use