Asked by Anonymous
If 3 sinb + 5 cosb =5 then show that 3 cosb - 5 sinb =±3
Answers
Answered by
oobleck
(3sinb+5cosb)^2 = 9sin^2b + 30sinb cosb + 25cos^2b
(3cosb-5sinb)^2 = 9cos^2b - 30sinb cosb + 25sin^2b
adding, you get
(3sinb+5cosb)^2 + (3cosb-5sinb)^2 = 9+25 = 34
5^2 + (3cosb-5sinb)^2 = 34
now finish it off
(3cosb-5sinb)^2 = 9cos^2b - 30sinb cosb + 25sin^2b
adding, you get
(3sinb+5cosb)^2 + (3cosb-5sinb)^2 = 9+25 = 34
5^2 + (3cosb-5sinb)^2 = 34
now finish it off
There are no AI answers yet. The ability to request AI answers is coming soon!
Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.