Math Problem Statement

Let f(x) = {6sin(x) + 2 if x <= 5π/6; mx + 2 if x >= 5π/6}. What must the value of m be so that the function f(x) is continuous everywhere? Give result in exact form.

Solution

To ensure the function f(x)f(x) is continuous everywhere, the two pieces of the function must be equal at the point where they meet, which is at x=5π6x = \frac{5\pi}{6}. Let's set the two expressions for f(x)f(x) equal to each other at x=5π6x = \frac{5\pi}{6}.

Given:

\begin{cases} 6 \sin(x) + 2 & \text{if } x \leq \frac{5\pi}{6} \\ mx + 2 & \text{if } x \geq \frac{5\pi}{6} \end{cases}$$ For continuity at $$x = \frac{5\pi}{6}$$, we need: $$6 \sin\left(\frac{5\pi}{6}\right) + 2 = m \left(\frac{5\pi}{6}\right) + 2.$$ Let's calculate $$\sin\left(\frac{5\pi}{6}\right)$$ and solve for $$m$$. $$\sin\left(\frac{5\pi}{6}\right) = \sin\left(\pi - \frac{\pi}{6}\right) = \sin\left(\frac{\pi}{6}\right) = \frac{1}{2}.$$ Substitute this value into the equation: $$6 \cdot \frac{1}{2} + 2 = m \left(\frac{5\pi}{6}\right) + 2.$$ Simplify the equation: $$3 + 2 = m \left(\frac{5\pi}{6}\right) + 2.$$ $$5 = m \left(\frac{5\pi}{6}\right).$$ Solve for $$m$$: $$m = \frac{5 \cdot 6}{5\pi} = \frac{6}{\pi}.$$ Therefore, the value of $$m$$ that makes the function $$f(x)$$ continuous everywhere is: $$\boxed{\frac{6}{\pi}}.$$ Would you like further details or have any questions? ### Related Questions: 1. How do you prove a function is differentiable? 2. What are some properties of continuous functions? 3. How do we handle piecewise functions in integration? 4. What are some other examples of functions where continuity needs to be checked? 5. How can we generalize continuity for multivariable functions? **Tip:** Remember, checking continuity at a point involves verifying both the limit and the function value at that point!

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Math Problem Analysis

Mathematical Concepts

Piecewise Functions
Continuity
Trigonometric Functions
Limits

Formulas

sin(π - x) = sin(x)
For continuity: f(a-) = f(a+)
Limit of sin(x) at specific points

Theorems

Continuity of Piecewise Functions

Suitable Grade Level

High School (Grades 11-12) or Early College