ANSWER : n² /m²+n²

Explanation : : Cosα /Cos β = n and Cos α/Sin β=m Cos α=nsin β=m cos β n² sin²β=mcos β n²(1-cos²β)=m²cos²β n²-n²cos² β=m²cos²β cos²β(m² + n²)=n² cos²β=n²/(m²+n²)

ANSWER : 2 sin²A-1

Explanation : : tan A = sin A /cos A cot A= cos A/sin A Sin A cos A(tan A-cot A) =sin A cos A(sin A/cos A-cos A/sin A) =sin²A-cos²A =sin²A-(1-sin²A) =2 sin²A-1 [Since sin²A + cos ²A=1]

ANSWER : 6 cm

Explanation : : XY=15 cm XZ=15 cm TX=XZ-ZT ZT=XZ-TX=(15-9)=6 cm RT=6 cm

ANSWER : 45°

Explanation : : Given: tan²Ɵ + 1 /tan²Ɵ =2 Let x = tan²Ɵ x+1/x=2 x²-2x+1=0 (x-1)²=0 x=1 x=1 tan²Ɵ =1 tan Ɵ = √1=1 tan ⁻¹(1)=45° Ɵ =45°

ANSWER : 90-B/2

Explanation : If x/y=3/4,the ratio of (2x+3y) and (3y-2x) is: opt1:3:1 opt2:1:1 opt3:2:1 opt4:3:2 ans: 3:1 Exp: Given x/y=3/4 To find :(2x+3y):(3y-2x) =2x+3y/3y-2x=2(x/y)+3 / 3-2(x/y) =2(3/4)+3 / 3-2(3/4) =3/2+3 / 3-3/2 =9/2 / 3/2 =3/1