if zeroes of p(x)=5x^2-7x+k are reciprocal of each other then find value of k

Answer 1

using the quadratic formula,

x = [7±√(49-20k)]/10
so,

(7+√(49-20k))/10 * (7-√(49-20k))/10 = 1
49-(49-20k) = 100
20k = 100
k = 5