Home » Further Mathematics » If sin x (frac{P – Q}{P + Q}), where 0(^o) (leq) x (leq) 90(^o), find 1…

If sin x (frac{P – Q}{P + Q}), where 0(^o) (leq) x (leq) 90(^o), find 1…

If sin x (frac{P – Q}{P + Q}), where 0(^o) (leq) x (leq) 90(^o), find 1 – tan(^2)x

Explanation

Let w be the adjacent side, then w(^2) = (P + q)(^2) = 4pq so that w = 2(sqrt{pq}) 

Since tan x (frac{p – q}{2sqrt{pq}}),

substituting; 1 – tan(^2)x = 1 – ((frac{p – q}{2sqrt{pq}}))(^2) 

= 1 – (frac{P^2 – 2pq + q^2}{4pq})

= (frac{4pq – p^2 + 2pq – q^2}{4pq})

Therefore, 1 – tan(^2)x = (frac{6pq – p^2 – q^2}{4pq})