Question

Choose the incorrect statement: (A) The value of Sine increases with increases,0° ≤ 0 ≤ 90°. (B) sin (A+B) = sin A + sin B (C) sec A = x² + y² 2xy is a possible equation for any real value of x and y (D) If sin A = sin B then ​

Answer 1

Answer:

A

x=y

As −1≤sinθ≤1

⇒0≤sin

2

θ≤1

⇒0≤

2xy

x

2

+y

2

≤1

Now using

2xy

x

2

+y

2

≥0⇒x

2

+y

2

≥0 ...(1)

And

2xy

x

2

+y

2

≤1⇒x

2

+y

2

≤2xy

⇒(x−y)

2

≤0⇒x=y ...(2)

and x,y



=0