Question

write all the values of p for which the quadratic equation x²+px+16=0 has equal roots

Answer 1

the discrimant of a quadratic equation

 I.e (ax² + bx + c =0 )   with equal root is given by b² - 4ac = 0

from the question 

x² + px +16 = 0

a = 1 b= p and c = 16 

b² = 4ac

p² = 4 × 1 × 16 

p² = 64

take the square root of both side

√p² = √64

p = 8