Question

if (tan theta - 1) × (tan theta + 1) = 0 ,
theta lies between 0 and 90 find theta​

Answer 1

Answer:

45°

Step-by-step explanation:

Solve using quadratic equation.

X = tan θ

$(X-1)(X+1)=0\\X=1, -1$

tan θ = tan 45°

θ = 45°

Answer 2

Answer:

teta=45degrees

Step-by-step explanation:

(tan teta-1)(tan teta+1)=(tan^2teta-1)=0

(a+b)(a-b)=a^2-b^2

tan^2 teta=1

tan teta=+-1 but teta belongs to 0 to90

so teta= 45