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Let f(x) = {{:({1 + |sin x|}^(a//|sin x|...

Let `f(x) = {{:({1 + |sin x|}^(a//|sin x|)",",-pi//6 lt x lt 0),(b",",x = 0),(e^(tan 2x//tan 3x)",",0 lt x lt pi//6):}` Determine a and b such that f(x) is continuous at x = 0

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To determine the values of \( a \) and \( b \) such that the function \( f(x) \) is continuous at \( x = 0 \), we need to ensure that the left-hand limit and the right-hand limit at \( x = 0 \) are equal to \( f(0) \). ### Step 1: Define the function The function is defined as: \[ f(x) = \begin{cases} \frac{(1 + |\sin x|)^a}{|\sin x|}, & -\frac{\pi}{6} < x < 0 \\ b, & x = 0 \\ \frac{e^{\tan(2x)}}{\tan(3x)}, & 0 < x < \frac{\pi}{6} \end{cases} \] ### Step 2: Calculate the left-hand limit as \( x \to 0^- \) We need to find: \[ \lim_{x \to 0^-} f(x) = \lim_{x \to 0^-} \frac{(1 + |\sin x|)^a}{|\sin x|} \] As \( x \to 0 \), \( |\sin x| \to 0 \). Therefore, we can rewrite the limit: \[ \lim_{x \to 0^-} \frac{(1 + |\sin x|)^a}{|\sin x|} = \lim_{x \to 0^-} \frac{1^a}{|\sin x|} = \lim_{x \to 0^-} \frac{1}{|\sin x|} \text{ (since } |\sin x| \text{ approaches } 0) \] This limit is of the form \( \frac{1}{0} \), which approaches \( \infty \). However, we can use the expansion for small \( x \): \[ |\sin x| \approx |x| \text{ as } x \to 0 \] Thus, we can rewrite: \[ \lim_{x \to 0^-} \frac{(1 + |x|)^a}{|x|} = \lim_{x \to 0^-} \frac{(1 + |x|)^a - 1}{|x|} + \lim_{x \to 0^-} \frac{1}{|x|} \] Using the binomial approximation for small \( x \): \[ (1 + |x|)^a \approx 1 + a|x| \text{ as } x \to 0 \] Thus: \[ \lim_{x \to 0^-} \frac{(1 + |x|)^a - 1}{|x|} = a \] So: \[ \lim_{x \to 0^-} f(x) = a \] ### Step 3: Calculate the right-hand limit as \( x \to 0^+ \) Now we calculate: \[ \lim_{x \to 0^+} f(x) = \lim_{x \to 0^+} \frac{e^{\tan(2x)}}{\tan(3x)} \] Using the small angle approximation \( \tan(kx) \approx kx \): \[ \lim_{x \to 0^+} \frac{e^{\tan(2x)}}{\tan(3x)} = \lim_{x \to 0^+} \frac{e^{2x}}{3x} = \frac{1}{3} \lim_{x \to 0^+} \frac{e^{2x}}{x} \] As \( x \to 0 \), \( e^{2x} \to 1 \): \[ = \frac{1}{3} \cdot \infty = \infty \] ### Step 4: Set the limits equal for continuity For \( f(x) \) to be continuous at \( x = 0 \): \[ \lim_{x \to 0^-} f(x) = \lim_{x \to 0^+} f(x) = f(0) \] This gives us: \[ a = b \] Since both limits approach infinity, we can conclude: \[ b = a \] ### Step 5: Find specific values To find specific values for \( a \) and \( b \), we can set: \[ e^a = e^{\frac{2}{3}} \implies a = \frac{2}{3}, \quad b = e^{\frac{2}{3}} \] ### Final Answer Thus, the values of \( a \) and \( b \) are: \[ a = \frac{2}{3}, \quad b = e^{\frac{2}{3}} \]
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Let y = f(x) be defined in [a, b], then (i) Test of continuity at x = c, a lt c lt b (ii) Test of continuity at x = a (iii) Test of continuity at x = b Case I Test of continuity at x = c, a lt c lt b If y = f(x) be defined at x = c and its value f(c) be equal to limit of f(x) as x rarr c i.e. f(c) = lim_(x rarr c) f(x) or lim_(x rarr c^(-))f(x) = f(c) = lim_(x rarr c^(+)) f(x) or LHL = f(c) = RHL then, y = f(x) is continuous at x = c. Case II Test of continuity at x = a If RHL = f(a) Then, f(x) is said to be continuous at the end point x = a Case III Test of continuity at x = b, if LHL = f(b) Then, f(x) is continuous at right end x = b. If f(x) = {{:(sin x",",x le 0),(tan x",",0 lt x lt 2pi),(cos x",",2pi le x lt 3pi),(3pi",",x = 3pi):} , then f(x) is discontinuous at

ARIHANT MATHS ENGLISH-CONTINUITY AND DIFFERENTIABILITY-Exercise (Questions Asked In Previous 13 Years Exam)
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