The equation 2x^2 + 2kx + (k + 2) = 0, where k is a constant, has two distinct real roots. Show that k satisfies k^2 – 2k – 4 > 0

Two distinct real roots means that we can use b^2-4ac>0 relationship for any ax^2+bx+c equation. Apply the above gives, 4k^2 - 42(k+2)>0 Simplifying gives, k^2 - 2k -4 >0

AT

Related Maths A Level answers

All answers ▸

How do I differentiate an algebraic expression? (e.g. y=3x^4 - 8x^3 - 3) [the ^ represents x being raised to a power]


y = 4x^3 - 5/x^2 Find dy/dx


For rectangles of area 100 m^2 what is the perimeter of the rectangle with the smallest perimeter?


How can I use the normal distribution table to find probabilities other than P(z<Z)?