Question

For what value of death of k the root of the quadratic equation k + 4 into x square + a + 1 x + 1 is equal to zero if the roots are equal

Answer 1

(k+4)xsquare+(a+1)x+1

discriminant =bsquare-4ac=0

(a+1)square-4(k+4)(1)=0

asquare+1+2a-4k-16=0

asquare+2a-15-4k=0

asquare+2a-15=4k

asquare+5a-3a-15=4k

a(a+5)-3(a+5)=4k

(a-3) (a+5)/4=k

a-3/4=k a+5/4=k