If 7sin^2 θ + 3cos^2 θ = 4, 0° < θ < 90 °, then the value of θ will b…

$ 7sin^2 θ + 3cos^2 θ = 4, 0° < θ < 90 °$

7sin²θ + 3 ( 1 - sin² θ  ) = 4                 { sin²θ  = 1 - cos² θ  }

4sin²θ + 3 = 4  

sin²θ = \(\frac{1 }{4}\)

sinθ = \(\frac{1 }{2}\)

And we know sinθ is \(\frac{1 }{2}\)  only if θ = 30°

Ans:- 30°