2014/116) What is the value of m in the quadratic equation $x^2-mx+4=0$ to have real and equal roots.

equal roots

discriminant = 0 ($b^2-4ac, a = 1 b = -m . c = 4$)

$m^2 - 4*4 = 0$ or m= 4 or -4

m = 4 means $^2-4x+4 = 0$   oots are 2 and 2
m = -4 means $^2+4x+4 = 0$r  roots 2 and -2

roots are real as well


refer to https://in.answers.yahoo.com/question/index?qid=20111021024215AACQbhH