1.Let f:[−1,1]→Bf : [-1, 1] \to Bf:[−1,1]→B be a function defined as f(x)=cot−1(2x3(1+x2))f(x) = \cot^{-1}\left(\frac{2x}{\sqrt{3}(1+x^2)}\right)f(x)=cot−1(3(1+x2)2x). If fff is both one-one and onto, then BBB is the intervala.(0,π3)(0, \frac{\pi}{3})(0,3π)b.[0,2π3)[0, \frac{2\pi}{3})[0,32π)c.[π3,2π3][\frac{\pi}{3}, \frac{2\pi}{3}][3π,32π]d.(π3,π)(\frac{\pi}{3}, \pi)(3π,π)Login to continueOnly logged in users canattempt or see the solution.