# i need help fast with these problems

**Question description**

1.The motion of a spring that is subject to a frictional force or a damping force (such as a shock absorber in a car) is often modeled by the product of an exponential function and a sine or cosine function. Suppose the equation of motion of a point on such a spring is

^{−1.9t}sin 2πt

*s*is measured in centimeters and

*t*in seconds. Find the velocity after

*t*seconds.

2.Find the *x*-coordinates of all points on the curve

f(x) = sin 2x − 2 sin x

at which the tangent line is horizontal. (Enter your answers as a comma-separated list. Use*n*to represent any integer.)

3.ind an equation of the tangent line to the curve at the given point.

^{2}9x,(0, 0)

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