Solve cos2A=sqrt(2)(cosA-sinA)cos2A=√2(cosA−sinA)?
2 Answers
Oct 21, 2017
See the answer below...
Explanation:
cos2A=sqrt2(cosA-sinA)cos2A=√2(cosA−sinA)
=>cos2A(cosA+sinA)=sqrt2(cos^2A-sin^2A)⇒cos2A(cosA+sinA)=√2(cos2A−sin2A)
=>cos2A(cosA+sinA)=sqrt2 cdot cos2A⇒cos2A(cosA+sinA)=√2⋅cos2A
=>cancel(cos2A)(cosA+sinA)=sqrt2 cdot cancel(cos2A
=>(cosA+sinA)=sqrt2
=>sin^2A+cos^2A+2sinAcosA=2 [squared both side]
=>1+sin2A=2
=>sin2A=1=sin90^@
=>2A=90^@
=>A=45^@ HOPE THE ANSWER HELPS...
THANK YOU...
Nov 9, 2017
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