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How do you solve an equation like x^2+3x-4=0

There are many ways of solving this equation, which is called a second order polynomial (where the order describes the highest power of x), let's focus on the most general for now: the quadratic formula. ...

Answered by Victor L. • Maths tutor

3256 Views

c is a positive integer. Prove that (6c^3+30c) / ( 3c^2 +15) is an even number.

Our starting equation (6c³+30c) / ( 3c² +15) can be factorised by 6c on the top row and 3 on the bottom row so you get 6c(c²+5) / 3(c²+5). Because (c²

Answered by Lenya A. • Maths tutor

6094 Views

A basketball player throws his ball vertically upwards with an initial speed of v=40 m/s. Ignore air resistance. What is the speed of the ball at half of the maximum height?

Since we are neglecting air resistance the energy of the ball is conserved. We set the gravitational potential energy to be U=0 at h=0. Applying conservation of energy at h=0 and h=h_max, we ge...

Answered by Alexandros M. • Physics tutor

5564 Views

How do I multiply two brackets without missing terms when multiplying?

In order to answer these sorts of questions where you have double brackets and need to expand them it is useful to use the FOIL (First Outer Inner Last) method. By using this systematic method it ensures ...

Answered by Andrew R. • Maths tutor

6580 Views

Explain why the product of nucleophilic addition of a cyanide ion to the ketone CH3COCH2CH3 shows no optical activity

The ketone group is planar and the cyanide ion has equal chance of attacking above or below the plane. Therefore a racemic mixture of the product is formed and the product shows no optical activity

Answered by Hannah T. • Chemistry tutor

2753 Views