A ball is thrown straight upward from the ground and attains a height of \( s(t)=-2 t^{2}+28 t+68 \mathrm{ft} \) above the ground after \( t \mathrm{sec} \). When does the ball reach the maximum height? What is the maximum height? a. The ball reaches the maximum height after 9 seconds; its maximum height is 302 ft.

\( \lim _ { z - 1 } \frac { 4 z + 3 } { 2 z + 1 } \)

Find differenthal equation of the primitue \( x y+x^{2} y+y^{2}=13 \)

Given that \( \int_{0}^{1}\left(2+3 \cos \frac{1}{2} x\right) d x=\int_{-1}^{2} e^{2 x+1} d x \), find the value of \( k \), giving your answer correct to 3 decimal places.

Given the differential equation \( \frac{dy}{dx} = 3y \) and the initial condition \( y(0) = 2 \), find the particular solution.

Jika \( m \) dan \( n \) adalah bilangan negatif dan berlaku \( \lim _{x \rightarrow n} \frac{4-\sqrt{m(x+n)}}{n-x}=n \), maka nilai dari \( m-n=\cdots \) (A) -9 (B) -7 (C) -5 (D) 7 (E) 9