Question

Find the values of k for which the equation 9x square +12 kx-1=0 has real roots

Answer 1

b*b-4ac
${b}^{2} - 4ac \geqslant 0 \\ 144 {k}^{2} + 36 \geqslant 0 \\ \\ k \geqslant 6 \div 12 \\ k \geqslant 1 \div 2$