The solutions are given in each case, so you can try them quickly. Solutions can be copied with **copy and paste**. Copy and paste may not work on a smartphone.

#### Algebra

Let s be positive.

Solution:

2hr

#### Integral calculus

Solution:

2

#### Trigonometry

Solution:

\cos \left(x\right)\times \sin \left(y\right)

or\cos x\times \sin y

Solution:

\cos \alpha

or\cos \left(\alpha\right)

Solution:

-\sin x

#### Physics

What is the kinetic energy E

_{kin}of a body of massm=60\unit{kg}

and speedv = 72\unit{\frac{km}{h}}

?Solution:

12\unit{kJ} = 12\unit{kNm} = 12000\unit{J} = 12000\unit{\frac{kg\times m^2}{s^2}}=0.012\unit{MJ}