Flag Trigonometry> Question no 61 and 62 both questions of t...
question mark

Question no 61 and 62 both questions of top math I will be greatly for your help plz ............................................... ...... .....,

Ashiah Kumar , 6 Years ago
Grade
anser 2 Answers
Susmita

Last Activity: 6 Years ago

I am writing P in place of theta.
acosP-bsinP=c
Take whole square.
a2cos2P+b2sin2P-2abcosPsinP=c2
or,a2cos2P+b2sin2P=c2+2absocPsinP......eq1
Now (asinP+bcosP)2
=a2sin2P+b2cos2P+2absinPcosP
=a2(1-cos2P)+b2(1-sin2P)+2absinPcosP
=a2+b2-(a2cos2P+b2sin2P)+2absinPcosP
=a2+b2-(c2+2absinPcosP)+2absinPcosP
=a2+b2-c2
so asinP+bcosP=root(a2+b2-c2) with a plus minus sign before it

Susmita

Last Activity: 6 Years ago

sinx+sin2x=1
Or,1-sin2x=sinx
or,cos2x=sinx....eq1
cos8x+2cos6x+cos4x
=sin4x+2sin3x+sin2x
=sin2x(sin2x+2sinx+1).....eq2.
Replace sin2x=1-sinx and factorize the term within first bracket.eq2 will become
(1-sinx)(1+sinx)(1+sinx)
=(1-sin2x)(1+sinx) 
=sinx(1+sinx)
=sinx+sin2x=1
none of the given options are correct.
 
 

Provide a better Answer & Earn Cool Goodies

Enter text here...
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments


Ask a Doubt

Get your questions answered by the expert for free

Enter text here...