All Exams Test series for 1 year @ ₹349 only
Question

Find k such that \(x^2 -2(k+1)x + (k^2+1)=0\) has distinct real roots.

This question was previously asked in
UPTET 2026 Paper 2 Social Studies Question Paper (3-Jul-2026) (Shift 1)
The correct answer is

k>0

For distinct real roots, the discriminant must be strictly positive: \(b^2-4ac>0\).

Here \(a=1,\ b=-2(k+1),\ c=(k^2+1)\), so \(4(k+1)^2 - 4(k^2+1) > 0\).

Dividing by 4: \((k+1)^2 - (k^2+1) > 0 \Rightarrow k^2+2k+1-k^2-1>0 \Rightarrow 2k>0\).

This simplifies to \(k>0\).

Was this answer helpful?

Similar Questions

  1. If x + y = 7 and xy = 10, find x2 + y2.

  2. If x + y + z = 0 and x2 + y2 + z2 = 2, find x4 + y4 + z4.

  3. Let x + y = 5 and x2 + y2 = 13. Find x and y.

  4. For what value of k does \(x^2 -(k+3)x + (k+2) = 0\) have equal roots?


Important Questions from Quadratic Equations

  1. If the graph of a quadratic polynomial lies entirely above x-axis, then which one of the following is correct?

  2. If the roots of the equation x 2+ px + q = 0 are tan 19° and tan 26°, then which one of the following is correct?

  3. If x 2- px + 4 > 0 for all real values of x, then which one of the following is correct?

  4. If 2 + i is a root of the equation x 2- ax + 1 = 0, then the value of a is:

  5. If \(\tan \left( {\frac{α }{2}} \right)\)  and  \(\tan \left( {\frac{β }{2}} \right)\)  are the roots of the equation 8x 2- 26x + 15 = 0, then the value of cos (α + β) will be

Need Expert Advice?
Upcoming Exams
MH SET
October 25, 2026
CTET
December 12, 2026
Test Series
UP TET img
Teaching
UPTET 2026 (Paper 1 & 2) Mock Test Series
257 Tests 16 Tests Free
2141 Attempts
4.6(18)
English, Hindi

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App