Find where the equation y = x^2 + x - 2 crosses the x-axis.

First, notice that any equation crosses the x-axis when y = 0.Second, notice that x2 + x - 2 = 0 is an example of a quadratic equation. So, we generally do 1 of 3 things (Factorise, Complete the square or use the Quadratic formula.)First test if it can be factorized. Look at all the ways 2 can be split, in this case ( 2 x 1 )Then, try finding pairs of these that add to make 1 and multiply to make -2, in this case ( +2 & -1) therefore, we can factorise:(x - 1)(x + 2) = 0Then solve, x - 1 = 0 and x + 2 = 0, which gives x = 1 and x = -2So, x2 + x - 2 = 0 crosses x-axis at x = 1 and x = -2

AR

Related Maths GCSE answers

All answers ▸

What is 3!/5! written in standard form?


ABC and BCD are two attached triangles, attached along line BC. AB = 5.8cm, AC=5.2cm, BD=4.3cm. Angle BDC = 30 degrees, and angle DCB is a right angle. Calculate angle CBA.


Mike, Sam and James play football. Mike scores 8 more goals than James. Sam scores 5 more goals than Mike. Altogether they score 72 goals. How many did Sam score?


In 2014, Donald's weekly pay was $640. In 2015, Donald's weekly pay was $668,80. Work out the percentage increase in Donald's pay between 2014 and 2015.