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Find 
lim_(x rarr(pi)/(2))(cot^(2)(x))/(1-sin(x))
Choose 1 answer:
(A) -1
(B) 
-(pi)/(2)
(C) 2
(D) The limit doesn't exist

Find limxπ2cot2(x)1sin(x) \lim _{x \rightarrow \frac{\pi}{2}} \frac{\cot ^{2}(x)}{1-\sin (x)} \newlineChoose 11 answer:\newline(A) 1-1\newline(B) π2 -\frac{\pi}{2} \newline(C) 22\newline(D) The limit doesn't exist

Full solution

Q. Find limxπ2cot2(x)1sin(x) \lim _{x \rightarrow \frac{\pi}{2}} \frac{\cot ^{2}(x)}{1-\sin (x)} \newlineChoose 11 answer:\newline(A) 1-1\newline(B) π2 -\frac{\pi}{2} \newline(C) 22\newline(D) The limit doesn't exist
  1. Understand Behavior of Function: First, let's understand the behavior of the function as xx approaches π/2\pi/2. The cotangent function, cot(x)\cot(x), is the reciprocal of the tangent function, tan(x)\tan(x), which means cot(x)=1/tan(x)\cot(x) = 1/\tan(x). As xx approaches π/2\pi/2, tan(x)\tan(x) approaches infinity because the angle is approaching 9090 degrees where the tangent function is not defined. Therefore, cot(x)\cot(x) approaches 00. However, we have cot2(x)\cot^2(x) in the numerator, which means we need to consider the square of cot(x)\cot(x) as xx approaches π/2\pi/2.
  2. Evaluate Limit Indeterminate Form: Now let's look at the denominator, 1sin(x)1 - \sin(x). As xx approaches π2\frac{\pi}{2}, sin(x)\sin(x) approaches 11. This means that the denominator, 1sin(x)1 - \sin(x), approaches 00. We have a situation where both the numerator and the denominator are approaching 00, which is an indeterminate form. This suggests that we may need to apply L'Hôpital's Rule to evaluate the limit.
  3. Simplify Expression: Before applying L'Hôpital's Rule, let's simplify the expression if possible. The expression cot2(x)\cot^2(x) can be written as cos2(x)sin2(x)\frac{\cos^2(x)}{\sin^2(x)}. So, the limit can be rewritten as:\newlinelimxπ2(cos2(x)sin2(x))/(1sin(x))\lim_{x \to \frac{\pi}{2}} \left(\frac{\cos^2(x)}{\sin^2(x)}\right) / (1 - \sin(x))\newlineThis is equivalent to:\newlinelimxπ2(cos2(x)sin2(x)(1sin(x)))\lim_{x \to \frac{\pi}{2}} \left(\frac{\cos^2(x)}{\sin^2(x) \cdot (1 - \sin(x))}\right)
  4. Apply L'Hôpital's Rule: Now we can apply L'Hôpital's Rule because we have an indeterminate form of 0/00/0. L'Hôpital's Rule states that if the limit as xx approaches aa of f(x)/g(x)f(x)/g(x) is 0/00/0 or /\infty/\infty, then the limit is the same as the limit of the derivatives of the numerator and the denominator. So we need to find the derivatives of cos2(x)\cos^2(x) and sin2(x)(1sin(x))\sin^2(x) \cdot (1 - \sin(x)) with respect to xx.
  5. Find Derivatives: The derivative of cos2(x)\cos^2(x) with respect to xx is 2cos(x)sin(x)-2\cos(x)\sin(x) using the chain rule. The derivative of sin2(x)\sin^2(x) with respect to xx is 2sin(x)cos(x)2\sin(x)\cos(x), and the derivative of sin3(x)-\sin^3(x) with respect to xx is 3sin2(x)cos(x)-3\sin^2(x)\cos(x). Therefore, the derivative of the denominator sin2(x)(1sin(x))\sin^2(x) \cdot (1 - \sin(x)) with respect to xx is xx11.
  6. Apply Derivatives to Rule: Now we can apply the derivatives to L'Hôpital's Rule:\newlinelimxπ22cos(x)sin(x)2sin(x)cos(x)3sin2(x)cos(x)\lim_{x \to \frac{\pi}{2}} \frac{-2\cos(x)\sin(x)}{2\sin(x)\cos(x) - 3\sin^2(x)\cos(x)}\newlineWe can simplify this by canceling out common factors of cos(x)\cos(x) and sin(x)\sin(x) where possible, keeping in mind that as xx approaches π2\frac{\pi}{2}, sin(x)\sin(x) approaches 11 and cos(x)\cos(x) approaches 00.
  7. Simplify and Substitute: After canceling out the common factors, we get:\newlinelimxπ2223sin(x)\lim_{x \to \frac{\pi}{2}} \frac{-2}{2 - 3\sin(x)}\newlineNow we can substitute x=π2x = \frac{\pi}{2} into the simplified expression:\newline\frac{\(-2\)}{\(2\) - \(3\)(\(1\))} = \frac{\(-2\)}{\(2\) - \(3\)} = \frac{\(-2\)}{\(-1\)} = \(2

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