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 ▸Why do you not add the 'plus c' when finding the area under a graph using integration even though you add it when normally integrating?
Let N be an integer not divisible by 3. Prove N^2 = 3a + 1, where a is an integer
How do you know if a function is odd or even?
A straight line passes through the point (2,1) and has a gradient of 3. Find the co-ordinates where the line crosses the x and y axes