Question

3.
If tan alpha = √a, where a is rational number
which is not a perfect square, then which
of the following is a rational number.
1) sin 2a 2) tan 2a 3)cos 2a 4) cota​

Answer 1

Answer:

α=30º or 60º

Step-by-step explanation:

sin(2α )=sin(60 )=1/2

tan(2α)=tan(60º )=√(3 )

cos(2α)=cos(60º )=√(3 )/2

cot(2α)=co(t60º )=1/√(3 )

Hence Sin2α is a rational number