Advertisements
Advertisements
Question
If x + y = 4 and xy = 2, find the value of x2 + y2
Advertisements
Solution
We have:
\[\left( x + y \right)^2 = x^2 + 2xy + y^2 \]
\[ \Rightarrow x^2 + y^2 = \left( x + y \right)^2 - 2xy\]
\[\Rightarrow x^2 + y^2 = 4^2 - 2 \times 2\] (\[\because\] \[x + y = 4 \text { and } xy = 2\])
\[\Rightarrow x^2 + y^2 = 16 - 4\]
\[ \Rightarrow x^2 + y^2 = 12\]
RELATED QUESTIONS
Factorize a3 x3 - 3a2bx2 + 3ab2 x - b3
(x + y)3 − (x − y)3 can be factorized as
Mark the correct alternative in each of the following: The factors of a2 − 1 − 2x − x2 are
Multiply: (2x + 3y)(2x + 3y)
Which of the following expressions has the value 37?
Write the coefficient of x2 and x in the following polynomials
`6 - 2x^2 + 3x^3 - sqrt(7)x`
Which of the following is correct?
In the given figure, the length of a green side is given by g and that of the red side is given by p.
Write an expression for the following pattern. Also write an expression if 100 such shapes are joined together.
Express the following properties with variables x, y and z.
Distributive property of multiplication over addition
Which of the following is an example of a monomial?
