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What is largest interval on which function sin^-1x is continuousa)[0,1] b)[-1,0] c)[-1,1] d)(-infinity,+infinity ) which one is correct ? |
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Answer» what is the largest interval on which function sin¯¹x is continuous ? solution : y = sin¯¹x is inverse trigonometric function. differentiating with RESPECT to x, dy/dx = 1/√(1 - x²) we SEE function will be differentiable in the interval (-1, 1) because there is no point between-1 and 1 where dy/dx is undefined. now we know, if a function is differentiable in (a, b) then function is continuous in [a, b] so function is continuous in [-1, 1] 2ND method : f(x) = sin¯¹x ⇒x = f(y) = siny range of f(y) = domain of f(x) we know, range of siny belongs to [-1, 1] so, domain of f(x) = [-1, 1] now you can apply limits for -1, 1 and 0. you will see, f(-1⁺) = f(-1) f(0¯) = f(0⁺) = f(0) f(1¯) = f(1) so function is continuous between -1 and 1 therefore OPTION (c) is [-1, 1] is correct. |
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