Math, asked by bishtrohit9906, 1 year ago

5sin+3cos=4
Find 3sin-5cos

Answers

Answered by agpg1908
3

Answer:

please mark it as a brainliest answer

Attachments:
Answered by Anonymous
1

ANSWER:-

Given:

5sin + 3cos= 4

To find:

Find the 3sin -5cos.

Solution:

5sin \theta + 3cos \theta = 4 \\ On \: squaring \: both \: sides; \\   =  > (5sin \theta + 3cos \theta) {}^{2}  = (4) {}^{2}  \\  \\  =  > 25 {sin}^{2}  \theta + 9 {cos}^{2}  \theta + 30sin \theta \: cos \theta = 16 \\  \\  =  > 16 {sin}^{2} \theta + 9 {sin}^{2}  \theta + 9 {cos}^{2}  \theta + 30sin \theta \: cos \theta = 16 \\  \\  =  > 9( {sin}^{2}  \theta + cos {}^{2}  \theta) + 30sin \theta \: cos \theta = 16(1 -  {sin}^{2}  \theta) \\  \\  =  > 9 + 30sin \theta \: cos \theta = 16 {cos}^{2}  \theta \\  \\  =  > 16 {cos}^{2}  \theta - 30sin \theta \: cos \theta = 9 \\  \\  =  > 16 {cos}^{2}  \theta  + 9 - 9 - 30sin \theta \: cos \theta = 9 \\  \\  =  > 16 {cos}^{2}  \theta + 9( {sin}^{2}  \theta +  {cos}^{2}  \theta) - 30sin  \theta \:cos \theta = 18 \\  \\  =  > 25 {cos}^{2}  \theta + 9 {sin}^{2}  \theta - 30sin \theta \: cos \theta = 18 \\  \\  =  > 9 {sin}^{2}  \theta + 25 {cos}^{2}  \theta  - 30sin \theta \: cos \theta = 18 \\  \\  =  > (3sin \theta - 5cos \theta) { }^{2}  = 18 \\  \\  =  > 3sin \theta - 5cos \theta = ± \sqrt{18}  =± 3 \sqrt{2}

Hope it helps ☺️

Similar questions