Recognize symmetry of sine function: To solve the limit limθ→0+(sin(π−θ))θ, we first need to recognize that sin(π−θ) is equivalent to sin(θ) due to the symmetry of the sine function.
Rewrite expression with limit: Since sin(θ) is continuous and differentiable at θ=0, and sin(0)=0, we can rewrite the expression as (sin(θ))θ.
Apply exponential and logarithmic functions: We can now apply the limit to the expression. However, the direct substitution of θ=0 would result in the indeterminate form 00. To resolve this, we can use the exponential and logarithmic functions to transform the expression.
Take natural logarithm of expression: Let's set y=(sin(θ))θ and take the natural logarithm of both sides to get ln(y)=θln(sin(θ)).
Apply L'Hôpital's Rule: Now we can find the limit of ln(y) as θ approaches 0 from the positive side: limθ→0+θln(sin(θ)).
Evaluate limit of cotangent function: We can use L'Hôpital's Rule to evaluate this limit because it is in the indeterminate form 0∗(−∞). Differentiate the numerator and the denominator with respect to θ.
Limit of natural logarithm is infinity: The derivative of the numerator ln(sin(θ)) with respect to θ is sin(θ)1⋅cos(θ)=cot(θ), and the derivative of the denominator θ with respect to θ is 1.
Limit does not exist: Applying L'Hôpital's Rule, we get limθ→0+1cot(θ), which simplifies to limθ→0+cot(θ).
Limit does not exist: Applying L'Hôpital's Rule, we get limθ→0+1cot(θ), which simplifies to limθ→0+cot(θ).As θ approaches 0 from the positive side, cot(θ) approaches infinity. Therefore, the limit of ln(y) as θ approaches 0 from the positive side is infinity.
Limit does not exist: Applying L'Hôpital's Rule, we get limθ→0+1cot(θ), which simplifies to limθ→0+cot(θ).As θ approaches 0 from the positive side, cot(θ) approaches infinity. Therefore, the limit of ln(y) as θ approaches 0 from the positive side is infinity.Since the limit of ln(y) is infinity, the limit of y=eln(y) is limθ→0+cot(θ)0, which means the original limit limθ→0+cot(θ)1 is limθ→0+cot(θ)0.
Limit does not exist: Applying L'Hôpital's Rule, we get limθ→0+1cot(θ), which simplifies to limθ→0+cot(θ).As θ approaches 0 from the positive side, cot(θ) approaches infinity. Therefore, the limit of ln(y) as θ approaches 0 from the positive side is infinity.Since the limit of ln(y) is infinity, the limit of y=eln(y) is limθ→0+cot(θ)0, which means the original limit limθ→0+cot(θ)1 is limθ→0+cot(θ)0.However, limθ→0+cot(θ)0 is not a finite number; it represents that the function grows without bound. Therefore, the limit does not exist in the real number system.
More problems from Csc, sec, and cot of special angles