Homework # 13 - Math 149
The problems on this homework must be done alone. The honor code is in effect.
First name: Last name:
For questions 1 - 3, take the derivative.
1. \(f(x) = \sin(x^2 + 2^x)\)
a. \( f'(x) = \cos(x^2+2^x)\)
b. \( f'(x) = \cos(x^2+2^x)(2x + (\ln 2)2^x)\)
c. \( f'(x) = \cos(2x + x2^{(x-1)})\)
d. \( f'(x) = \cos(2x + (\ln 2)2^x)\)
e. \( f'(x) = \sin(x^2 + 2^x)(2x + x 2^{(x-1)})\)
2. \(f(x) = 2^{2x}\)
a. \(f'(x) = (2x) 2^{(2x - 1)}\)
b. \(f'(x) = (2x) 2^{2x}\)
c. \(f'(x) = x 2^{2x}\)
d. \(f'(x) = (\ln 2) 2^{2x}\)
e. \(f'(x) = (2 \ln 2) 2^{2x}\)
3. \(h(x) = \frac{e^{(\sin x)}}{x}\)
a. \(h'(x) = \frac{e^{(\sin x)}(\cos x) x - e^{(\sin x)}}{x^2}\)
b. \(h'(x) = e^{(\sin x)}\)
c. \(h'(x) = \frac{e^{(\sin x)} - e^{(\sin x)}(\cos x)x}{x^2}\)
d. \(h'(x) = e^{(\sin x)} - e^{(\sin x)}(\cos x) x\)
e. \(h'(x) = \frac{e^{(\sin x)} - e^{(\cos x)}x}{x^2}\)
4. If \(\sin(xy) = y\), find \(\frac{dy}{dx}\)
a. \(\frac{dy}{dx} = \frac{y\cos(xy)}{1-x\cos(xy)}\)
b. \(\frac{dy}{dx} = \frac{y\cos(xy)}{1+x\cos(xy)}\)
c. \(\frac{dy}{dx} = \frac{-y\cos(xy)}{1+x\cos(xy)}\)
d. \(\frac{dy}{dx} = \cos(xy)\)
e. \(\frac{dy}{dx} = y\cos(xy)\)
5. Find \(\frac{dy}{dx}\) if \(x^3y + x + y^2 = 11\).
a. \(\frac{dy}{dx} = \frac{-3x^2y-1}{x^3+2y}\)
b. \(\frac{dy}{dx} = \frac{x^3+2y}{-3x^2y-1}\)
c. \(\frac{dy}{dx} = 3x^2 + 1 + 2y\)
d. \(\frac{dy}{dx} = 3x^2y + x^3 + 1 + 2y\)
e. \(\frac{dy}{dx} = 3x^2y + 1 + 2y\)
6. Find the equation of the tangent line to the curve \(x\sin y = 2 y\) at the point \( (\pi, \frac{\pi}{2}\)
a. \( y = 2x - \frac{\pi}{2}\)
b. \( y = 2x - \frac{3\pi}{2}\)
c. \( y = \frac{1}{2} x - \frac{\pi}{2}\)
d. \( y = \frac{1}{2} x \)
e. \( y = x - \frac{\pi}{2}\)
7. A spherical balloon is inflated with gas at the rate of 400 cubic centimeters per second (that is, the volume of the sphere is increasing at a rate of 400 cubic centimeters per second). How fast is the radius of the balloon increasing when the radius is 50 cm? The volume of a sphere is \(\frac{4}{3}\pi\) times the radius cubed.
a. \(\frac{0.02}{\pi}\) cm/s
b. \(\frac{0.04}{\pi}\)cm/s
c. \(\frac{0.2}{\pi}\) cm/s
d. \(\frac{0.4}{\pi}\) cm/s
e. 2 \(\pi\) cm/s