Sign in
Please select an account to continue using cracku.in
↓ →
Suppose k is any integer such that the equation $$2x^{2}+kx+5=0$$ has no real roots and the equation $$x^{2}+(k-5)x+1=0$$ has two distinct real roots for x. Then, the number of possible values of k is
$$2x^{2}+kx+5=0$$ has no real roots so D<0
$$k^2-40\ <0$$
$$\left(k-\sqrt{40}\right)\left(k+\sqrt{40}\right)<0$$
$$k\in\left(-\sqrt{40},\sqrt{40}\right)$$
$$x^{2}+(k-5)x+1=0$$ has two distinct real roots so D>0
$$\left(k-5\right)^2-4>0$$
$$k^2-10k+21>0$$
$$\left(k-3\right)\left(k-7\right)>0$$
$$k\in\left(-\infty\ ,3\right)∪\left(7,\infty\ \right)$$
Therefore possibe value of k are -6, -5, -4, -3, -2, -1, 0, 1, 2
In 9 total 9 integer values of k are possible.
Click on the Email ☝️ to Watch the Video Solution
Create a FREE account and get:
Book Free CAT Mentorship
Get personalized CAT strategy from a 99%iler
500+ students mentored
OTP Verification
Enter the 6-digit code sent to your phone
Booking Summary
Enter OTP
Didn't receive the OTP?
Educational materials for CAT preparation