Top answers

When do I use Sin, Cos or Tan?

You use these functions when you either have a length and an angle and you are looking for a length or when you have two lengths and are looking for an angle. There is a simple way to remember which one to u...
AC
Answered by Aaron C. • Maths tutor
13390 Views

There are 30 yellow sweets and 10 black sweets in a bag. Two sweets are taken out at random without replacement. Work out the probability that the two sweets are the same colour.

It is important before proceeding with the question to note down a few key facts. As can be seen by the question there are 40 sweets in total. With probability questions in general it can be easy to remember...
JT
Answered by James T. • Maths tutor
9672 Views

Write y = x^2 + 4x + 6 in the form y = (x + a)^2 + b. What is the minimum value of y?

This is an example of completing the square. Notice that when we expand y = (x + a)^2 + b we get y = x^2 + 2ax + a^2 + b. By comparing coefficients (ie, making sure the number x is multiplied by and the cons...
NS
Answered by Naomi S. • Maths tutor
8383 Views

x^2 - 10x + 21 = 0

First, factorise the quadratic equation. Find two numbers that multiply to give 21 and add to give 10. 7 and 3 (x-7)(x-3)=0 Now find the value x so that when these brackets are multiplied together the answer...
BS
Answered by Ben S. • Maths tutor
5050 Views

A is the point with coordinates (1, 3) B is the point with coordinates (–2, –1) The line L has equation 3y = 4 – 2x Is line L parallel to AB?

No it is not parallel, here is the reasoning. First we work out the gradient of the line AB. We do this by using the gradient formula (Y2-Y1)/(X2-X1). Our points are A=(1,3) rewritten as (X1,Y1) and B=(-2,-1...
EL
Answered by Emily L. • Maths tutor
13873 Views