Rationalise sina + cosa/sina - cosa
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Answer:
cosA−sinA+1cosA+sinA−1
=(cosA−sinA+1)(cosA+sinA+1)(cosA+sinA−1)(cosA+sinA+1)
=(cosA+1¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯−sinA)(cosA+1¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯+sinA)(cosA+sinA¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯−1)(cosA+sinA¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯+1)
=(cosA+1)2−(sinA)2(cosA+sinA)2−12
=cos2A+2cosA+1−sin2Acos2A+sin2A+2sinAcosA−1
=cos2A+2cosA+cos2A1+2sinAcosA−1(∵ cos2A+sin2A=1)
=2cos2A+2cosA2sinAcosA
=2cos2A2sinAcosA+2cosA2sinAcosA
=cosAsinA+1sinA
=cotA+cosecA
=cosecA+cotA
Proved.
Step-by-step explanation:
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