If x + y = 7 and xy = 10, find x2 + y2.
29
Use the identity \(x^2 + y^2 = (x+y)^2 - 2xy\).
Substituting the given values, \(x^2 + y^2 = 7^2 - 2(10) = 49 - 20\).
This gives \(x^2 + y^2 = 29\).
Similar Questions
If x + y + z = 0 and x2 + y2 + z2 = 2, find x4 + y4 + z4.
Let x + y = 5 and x2 + y2 = 13. Find x and y.
For what value of k does \(x^2 -(k+3)x + (k+2) = 0\) have equal roots?
Find k such that \(x^2 -2(k+1)x + (k^2+1)=0\) has distinct real roots.
Important Questions from Quadratic Equations
If the graph of a quadratic polynomial lies entirely above x-axis, then which one of the following is correct?
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?
If x 2- px + 4 > 0 for all real values of x, then which one of the following is correct?
If 2 + i is a root of the equation x 2- ax + 1 = 0, then the value of a is:
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
