Grade 11Trigonometry
Prove thatCos²A+cost(A+B)-2cosA.cosB.cos(A+B)=sin²B
Prove that
Cos²A+cost(A+B)-2cosA.cosB.cos(A+B)=sin²B
1 Answer
Arun
Approved Tutor Answer8 Years agoDear student
Cos²A + cos(A+B) [cosA cosB - sinA sinB- 2 cosA cosB]
= cos²A - cos(A+B) cos(A-B)
= Cos²A - cos²A + sin²B
= Sun²B
Regards
Arun (askIITians forum expert)
Other Related Questions on trigonometry
In ABC, if cot A+cot B+cot C = cosecA cosecB cosecC, then prove that ABC is right angle triangle.
In ABC, if cot A+cot B+cot C = cosecA cosecB cosecC, then prove that ABC is right angle triangle.
trigonometry
Last Activity: 3 Years ago
- Find the general solution of equation tan3∂=cot2∂
For all angles between -720 and +720
- Find the general solution of equation tan3∂=cot2∂
For all angles between -720 and +720
trigonometry
Last Activity: 4 Years ago
Derive a formula for the area of the triangle, given b, A, B, and C. That is, derive the formula: (b^2sinAsinC)/(2sinB)
Derive a formula for the area of the triangle, given b, A, B, and C. That is, derive the formula: (b^2sinAsinC)/(2sinB)
trigonometry
Last Activity: 4 Years ago
WHAT IS THE LIMIT WHEN X TOWARDS TO 0 OF sin6x/5x ? lim𝑥→0 𝑠𝑖𝑛6𝑥/5𝑥
WHAT IS THE LIMIT WHEN X TOWARDS TO 0 OF sin6x/5x ? lim𝑥→0 𝑠𝑖𝑛6𝑥/5𝑥
trigonometry
Last Activity: 4 Years ago