GUJCET 2026 Math Paper

Concept:The inverse cosine function is defined only on its principal-value branch.Explanation:The cosine function is not one-one over all real numbers.So, its inverse is defined by restricting the output to a standard interval.The principal value branch of $\cos^{-1} x$ is $[0,\pi]$.This means every value returned by $\cos^{-1} x$ lies between $0$ and $\pi$, inclusive.Given $y=\cos^{-1}x$, we get $0 \le y \le \pi$.The endpoints are included because $\cos^{-1}(1)=0$ and $\cos^{-1}(-1)=\pi$.This interval matches option B.Answer:$0 \le y \le \pi$Therefore, the correct option is B.