Register
If cosA=3√2/5,then show that cos2A=11/25
18.0k views
3 votes
If cosA=3√2/5,then show that cos2A=11/25

User Ramprasath Selvam
by
8.2k points

1 Answer

5 votes

Answer:

Explanation:

Cos 2A = 2Cos² A - 1


= 2*((3√(2))/(5))^(2)-1\\\\=2*((3^(2)*(√(2))^(2))/(5^(2)))-1\\\\=2*(9*2)/(25) - 1\\\\=(36)/(25)-1\\\\=(36)/(25)-(25)/(25)\\\\=(11)/(25)

User Svinec
by
7.5k points
← Prev Question Next Question →

Related questions

User Runita
asked Jun 20, 2024 167k views
Using the half-angle formula, suppose cos2A=(2)/(9), and 2A is an angle in the Fourth Quadrant. Then cosA
Runita asked Jun 20, 2024
by Runita
8.8k points
1 answer
5 votes
167k views
User Coffeduong
asked Mar 24, 2017 96.1k views
Prove cosA x cos2A x cos4A x cos8A = sin16A/16sinA
Coffeduong asked Mar 24, 2017
by Coffeduong
7.5k points
1 answer
0 votes
96.1k views
User Eriq
asked Jan 14, 2019 118k views
Solve: CosA+Cos2A+Cos3A= 0
Eriq asked Jan 14, 2019
by Eriq
8.4k points
1 answer
3 votes
118k views
Ask a Question
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.5m questions

12.2m answers

Other Questions

How do you estimate of 4 5/8 X 1/3
A bathtub is being filled with water. After 3 minutes 4/5 of the tub is full. Assuming the rate is constant, how much longer will it take to fill the tub?
i have a field 60m long and 110 wide going to be paved i ordered 660000000cm cubed of cement  how thick must the cement be to cover field
Write words to match the expression. 24- ( 6+3)
The cost of 5 similar digital cameras and 3 similar video cameras is 3213. Each video camera costs 4 times as much as each digital camera. John buys a digital camera and a video camera. How much does he
Link Copied!