Register
Cos4A+sin4A-2cos2Asin2A=(2cos2A-1)2 prove it.​
18.4k views
12 votes
Cos4A+sin4A-2cos2Asin2A=(2cos2A-1)2 prove it.​

User Tozka
by
3.5k points

1 Answer

1 vote

cos4A-sin4A=2cos2A-1

proved below.

Explanation:

Given:

cos^4A-sin^4A=2cos^2A-1

LHS=cos^4A-sin^4A

=[cos^2A]^2-[sin^2A]^2

=[cos^2A+sin^2A][cos^2A-sin^2A]

=[1][cos^2A-(1-cos^2A)] [ cos^2A+sin^2A=1]

=[cos^2A-1+cos^2A]

=2cos^2A-1

=RHS.

User Vijay Sali
by
3.9k points
Ask a Question
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

3.6m questions

4.6m answers

Other Questions

A study was completed in Florida. In southern Florida, the study involved 3,000 patients; 54% of them experienced flulike symptoms during the same month. The study had a margin of error of 1.8%. What does
Solve for x in the equation 3 x squared minus 18 x + 5 = 47. (I need this to be an answer like X=3+\_ square root 23)
Can someone help me plz I have to Turn 27/9 in simplest
The sanchez family goes out for dinner, and the price of the meals is $60. The sales tax on the Meals is 7 percent, and they also want to leave a 15 percent tip. What is the total cost of the meal? Analyze
Simplify: 10 ÷ [(5 + 2) − 5]
Link Copied!