Advertisements
Advertisements
प्रश्न
If x + y = 4 and xy = 2, find the value of x2 + y2
उत्तर
We have:
\[\left( x + y \right)^2 = x^2 + 2xy + y^2 \]
\[ \Rightarrow x^2 + y^2 = \left( x + y \right)^2 - 2xy\]
\[\Rightarrow x^2 + y^2 = 4^2 - 2 \times 2\] (\[\because\] \[x + y = 4 \text { and } xy = 2\])
\[\Rightarrow x^2 + y^2 = 16 - 4\]
\[ \Rightarrow x^2 + y^2 = 12\]
APPEARS IN
संबंधित प्रश्न
Get the algebraic expression in the following case using variables, constants and arithmetic operation.
Subtraction of z from y
Factorize a2 + 2ab + b2 - c2
Factorize `2x^2 - 5/6x + 1/12`
Factorize the following expressions:
32a3 + 108b3
If a2 + b2 + c2 = 20 and a + b + c = 0, find ab + bc + ca.
If a2 + b2 + c2 = 250 and ab + bc + ca = 3, find a + b + c.
(x + y)3 − (x − y)3 can be factorized as
Multiply: (2x + 5y + 6)(3x + y - 8)
When y = –1, the value of the expression 2y – 1 is 3
Shashi used addition to solve a word problem about the weekly cost of commuting by toll tax for ₹ 15 each day. Ravi solved the same problem by multiplying. They both got the correct answer. How is this possible?
