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How do you 'complete the square' of a quadratic equation?

To complete the square, we need to rearrange the quadratic equation in the form of ax 2 + bx + c into the form r(x + p) 2 + q, where our task is to find the values of the unkowns of r, p and q. Let's take th...
RB
Answered by Ryan B. • Maths tutor
3512 Views

Identify three types of long-term memory and give an example of each type

Long-term memory is one of the two storage types of memory. Long-term memories are memories that we are able to keep over a timescale of a couple of minutes to a whole lifetime. There are two types of long-t...
BW
16351 Views

Using the trigonometric identity (sinx)^2 + (cosx)^2 = 1, show that (secx)^2 = (tanx)^2 + 1 is also a trigonometric identity.

We can divide by (cosx)^2 across the identity (sinx)^2 + (cosx)^2 = 1 (which can be derived from properties of the unit circle and a bit of Pythagoras’ theorem) to achieve [(sinx)^2 / (cosx)^2] + [(cosx)^2 /...
AB
Answered by Annie B. • Maths tutor
4232 Views

These are the selling prices of 5 houses in 2007: £145 000, £170 000, £215 000, £90 000, £180 000 (a) Work out the mean selling price.

The mean is also known as the average. To work out the mean you need to add all the house prices together and then divide by the number of houses. So in this example the total price of the houses is 145000+1...
JP
Answered by James P. • Maths tutor
3380 Views

The random variable J has a Poisson distribution with mean 4. Find P(J>2)

P(J>2) = P(J=0)+P(J=1) [split it up] P(X=t)= (V^t)/t!*e^V where V=4 in this case [use the formula] P(J>2) = 4^0/0!*e^4 + 4^1/1!*e^4 =1/e^4 + 4/e^4 = 5e^-4 which is roughly 0.0916
NC
Answered by Nathan C. • Maths tutor
4646 Views