Please give solution of example 15.

Example 15: Prove  that  sin   θ - cos   θ + 1 sin   θ + cos   θ - 1 = 1 sec   θ - tan   θ  using the identity sec2  θ  = 1 + tan2  θ .

Dear student,

Example 15: Prove that sinθ-cosθ+1sinθ+cosθ-1=1secθ-tanθTaking LHS , divide by cosθ in numerator and denominatorsinθ-cosθ+1sinθ+cosθ-1=sinθcosθ-cosθcosθ+1cosθsinθcosθ+cosθcosθ-1cosθ                        =tanθ+secθ-1tanθ-secθ+1                             =tanθ+secθ-1tanθ-secθ+1 ×tanθ-secθtanθ-secθ                       =tanθ+secθtanθ-secθ-1×tanθ-secθtanθ-secθ+1tanθ-secθ                       =tan2θ-sec2θ-tanθ+secθtanθ-secθ+1tanθ-secθ1+tan2θ=sec2θsec2θ-tan2θ=1                      =-1-tanθ+secθtanθ-secθ+1tanθ-secθ                      =-tanθ-secθ+1tanθ-secθ+1tanθ-secθ=-1tanθ-secθ                      =-1-secθ-tanθ=1secθ-tanθ  =RHS
Regards

  • 0
What are you looking for?