if 5 sin A + 7 cos A = 7 show that
7 sin A-5 cos A = ± 5
Answers
Answered by
3
Step-by-step explanation:
Given:
5 sinA+7 cosA =7
so,
(5 sinA +7cosA)2+(7sinA -5cosA)2
=25 sin2A+49 cos2A+ 70sinA.cosA+ 49 sin2A+25cos2A-70sinA.cosA
=74
therefore ,
49+(7sinA-5cosA)2 =74
7sinA-5cosA=+5 or,
7sinA-5cosA=-5
Answered by
1
Answer:
7sinA-5cosA=-5
Step-by-step explanation:
answer for ur question
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