Monday

December 22, 2014

December 22, 2014

Posted by **James** on Tuesday, September 17, 2013 at 10:25am.

(sinA cosA)

show that

A^2=(cos2A sin2A)

(sin2A cos2A)

- further Mathematics -
**Steve**, Tuesday, September 17, 2013 at 2:01pmA^2 = (cosA-sinA)^2 (sinAcosA)^2

= (cos^2A-2sinAcosA+sin^2A)(sin^2Acos^2A)

= (1-2sinAcosA)(1/4)(2sinAcosA)^2

= (1/4)(1-sin2A)(sin2A)(sin2A)

Hmmm. What if A = -pi/4?

(1/√2 + 1/√2)(-1/√2 * 1/√2) =? (0)(0)

-1/√2 =? 0

Nope. I don't think it's true. Typo?

**Answer this Question**

**Related Questions**

trig - Prove: 1/cos2A+sin2A/cos2A=sinA+cosA/cosA-sinA

trig - Prove: 1/cos2A+sin2A/cos2A=sinA+cosA/cosA-sinA

math - how do you solve this.prove: cos2A plus cosA divided by sin2A minus sinA ...

MathS triG - 1 .If tanA=1/3 and tanB=1/7 (both A and B are acute),calculate ...

maths Pls help trig - 1 .If tanA=1/3 and tanB=1/7 (both A and B are acute),...

further mathematics - Let P=(cosA sinA) (sinA cosA) Q=(cosB sinA) (sinB cosA) ...

precal- PLEASE HELP! - Given:cosA= 4/5 0(less than or equal to)A(less than of ...

Maths - Hi, can someone give me the answer to this question: secA-tanA=1/4. Find...

trig - CosA x cos2A + ((sin2A)^2)/2cosA

trig - Please help me how to do this: 1) 1 + sina*cosa / (cosa + sina)^2 = 2) ...