what is largest interval on which function sin^-1x is continuous
a)[0,1]
b)[-1,0]
c)[-1,1]
d)(-infinity,+infinity )
which one is correct ?
Answers
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.
Answer:
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