Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 10 Answered

If SinA + 2CosA = 1 then prove that 2SinA-CosA = 2
Asked by Akriti | 22 Aug, 2012, 05:30: PM
Expert Answer
Given, sin A + 2 cos A = 1
Squaring both sides, we get,
sin2A + 4 cos2A + 4sinA cosA = 1
4 cos2A + 4sinA cosA = 1 - sin2A = cos2A
3 cos2A + 4sinA cosA = 0                ... (i)
 
Now, (2sinA - cosA)2 = 4sin2A + cos2A - 4sinA cosA
                             = 4sin2A + cos2A + 3cos2A          [Using (i)]
                             = 4 (sin2A + cos2A) = 4
Thus, 2sinA - cosA = 2
Hence, proved.
Answered by | 22 Aug, 2012, 11:05: PM
CBSE 10 - Maths
Asked by Bavashreelogasundaram | 22 Sep, 2022, 08:26: PM
ANSWERED BY EXPERT
CBSE 10 - Maths
Asked by padmajabchannammanavar | 08 Jun, 2022, 07:28: AM
ANSWERED BY EXPERT
CBSE 10 - Maths
Asked by sonymeitei23 | 07 Jun, 2022, 05:38: AM
ANSWERED BY EXPERT
CBSE 10 - Maths
Asked by prathibhakethavath2 | 03 May, 2022, 06:53: PM
ANSWERED BY EXPERT
CBSE 10 - Maths
Asked by ankitakulhar075 | 03 Apr, 2022, 08:43: PM
ANSWERED BY EXPERT
CBSE 10 - Maths
Asked by adinaditi29 | 14 Mar, 2022, 12:02: PM
ANSWERED BY EXPERT
CBSE 10 - Maths
Asked by 5533 | 21 Oct, 2021, 09:58: PM
ANSWERED BY EXPERT
CBSE 10 - Maths
Asked by anjaligavit77.10dgatl | 21 Oct, 2021, 05:09: PM
ANSWERED BY EXPERT
CBSE 10 - Maths
Asked by ambarishpatil7 | 28 Sep, 2021, 08:49: PM
ANSWERED BY EXPERT
CBSE 10 - Maths
Asked by patelsahil200306 | 29 Jul, 2021, 05:07: PM
ANSWERED BY EXPERT

Start your hassle free Education Franchisee and grow your business!

Know more
×