sinθ cosθ [sin(90∘−θ) cosecθ + cos(90∘−θ) secθ]
2
0
1
-1
= sinθ cosθ [cosθ cosecθ + sinθ secθ]
= sinθ cosθ [cosθsinθ + sinθcosθ]
= sinθ cosθ [(sin2θ+cos2θ)sinθcosθ]
= 1
Prove that:
(i) sin θ cos (90∘−θ)+sin(90∘−θ)cos θ=1
(ii) sin θcos (90∘−θ)+cos θsin (90∘−θ)=2
(iii) sin θ cos(90∘−θ)cos θsin (90∘−θ)+cos θ sin (90∘−θ)sin θcos (90∘−θ)=1
(iv) cos(90∘−θ)sec(90∘−θ)tan θcosec(90∘−θ)sin(90∘−θ)cot(90∘−θ)+tan(90∘−θ)cot θ=2
(v) cos(90∘−θ)1+sin(90∘−θ)+1+sin(90∘−θ)cos(90∘−θ)=2cosec θ
(vi) sec(90∘−θ)cosec θ−tan(90∘−θ)cot θ+cos225∘+cos265∘3 tan 27∘ tan 63∘=23
(vii) cot θ tan(90∘−θ)−sec(90∘−θ)cosec θ+√3 tan 12∘ tan 60∘ tan 78∘=2
1+sin(90∘−θ)−cos2(90∘−θ)cos(90∘−θ) [1+sin(90∘−θ)]=