The equation kx2+4x+(5−k)=0kx^2 + 4x + (5 - k) = 0kx2+4x+(5−k)=0, where k k\,k is a constant, has 2 different real solutions for xxx.
Show that k k\,k satisfies
k2−5k+4>0. k^2 - 5k + 4 > 0. k2−5k+4>0.Hence find the set of possible values of kkk.
18 exam-style questions on Edexcel A Level Old Maths Algebra and Functions 1. Each one has a worked solution and a mark scheme showing where the marks go.