Math, asked by lat5hankitasanjan, 1 year ago

Tan A + Sec A - 1/ tan A + Sec A + 1

Answers

Answered by daravindnaik
0
((tan A+sec A)+1)/(tan A-sec A)-1) = (1+sin A) /cos A 
Take the left hand side 
[(sinA/cosA) + (1/cosA) + 1] / [(sinA/cosA) - (1/cosA) -1] 
[((sinA+1)/cosA) + 1] / [(sinA-1)/cosA) -1] 
[(sinA+1+cosA) / cosA] / [(sinA-1-cosA) / cosA] 
(sinA+1+cosA) / (sinA-1-cosA) 
Multiply both numerator and denominator by (sinA-1+cosA) 
(sinA+1+cosA)(sinA-1+cosA) / (sinA-1-cosA)(sinA-1+cosA) 
[(sinA+1)² - cos²A] / [(sinA-cosA)² -1] 
(sin²A+2sinA+1-cos²A) / (sin²A-2sinAcosA+cos²A-1) 
(sin²A+2sinA+1-(1-sin²A)) / (sin²A+cos²A-2sinAcosA-1) 
(sin²A+2sinA+1-1+sin²A) / (sin²A+cos²A-2sinAcosA-1) 
(2sin²A+2sinA) / (1-2sinAcosA-1) 
2sinA(sinA+1) / 2sinAcosA <-- cancel out 2sinA 
(1+sinA) / cosA 

LHS=RHS so it is proven. 

Identities used: 
tanA = sinA/cosA 
secA = 1/cosA 
sin²A+cos²A = 1
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