Search over 10,000 free study notes

4-[(x+3)*((x-2)/(x^2 +5x +6))]

4-[(x+3)(x-2)/(x^2 +5x +6))]

factorise denominator 

4-[(x+3)(x-2)/(x+3)(x+2)]

cancel down (x+3)

4-[(x-2)/(x+2)]

expand 

4(x+...

dy/dx = 3x^2-2x+6

At (1,5), dy/dx = 7. 7 is the gradient of the tangent, therefore the gradient of the normal at (1,5) is -1/7.

There are, mainly, three ways of doing it easily:
Substitution: It consists in modifying one of the equations in such a way that x is expressed in terms of y  (or y in terms of x) and then substitut...

There are a few different ways to approach this problem. The most obvious is to attempt to factorise x³ + 2x² - 9x - 18. However it is very difficult to approach the problem like thi...

6x^2 + 7x + 2 can be written in the form ax^2 + bx + c. In order to factorise this I use the following method which can be used to factorise similar equations. Multiply 'a' and 'c' to get ac (here this is...