Q.

The range of f(x)=4sin-1(x2x2+1) is                [2023]

1 [0,2π)  
2 [0,π]  
3 [0,2π]  
4 [0,π)  

Ans.

(1)

Given,  4sin-1(x2x2+1)

x2x2+1=x2+1-1x2+1=1-1x2+1

x2≥0; x2+1≥1  ∴  0<1x2+1≤1⇒-1≤-1x2+1<0;

0≤1-1x2+1<1; 0≤4sin-1(x2x2+1)<2π