Page 46 - CITS - WCS - Electrical - Hindi

वक शॉप कै लकु लेशन & साइंस - CITS

x + y = 16 + 24
2
2
x + y 2 = 40
2
4 यिद x - y = 7 और xy = 60 तो x4 + y4 का मान ात कर
(x - y) 2 = x + y - 2xy = 7
2
2
2
x + y - 2 x 60 = 49
2
2
x + y = 169
2
2
(x + y ) = (169) (दोनों तरफ वग ल )
2
2
2 2
x + y + 2x y = (169) 2
4
4
2 2
x + y + 2(xy) = 28561
2
4
4
x + y + 2(60) = 28561
4
2
4
x + y + 2(3600) = 28561
4
4
x + y + 7200 = 28561
4
4
x + y = 28561 - 7200
4
4
x + y = 21361
4
4
5 x + y = ; x - y = का मान ात कीिजए 8 x y (x + y )
2
2
3
5
x + y = ; x - y = (दोनों तरफ वग ल )
3
5
(x + y) = 5; (x - y) = 3
2
2
समीकरण हल कर
(x + y) = x + y + 2xy = 5
2
2
2
(x - y) = x + y - 2xy = 3
2
2
2
----------------------------------------
2 (x + y ) = 8
2
2
(x + y ) = = 4
2
2
= x + y + 2xy = 5
2
2
= x + y - 2xy = 3
2
2
(-) (-) (+) (-)
-------------------------------------------
4xy = 2
-------------------------------------------
2 1
xy =
4 2
1
8 xy (x + y ) = 8 x x 4
2
2
2
= 4 x 4 = 16
§ 1 · 1
a
6 If ¨ ¸ = 6. Find the value of a +
2
© a ¹ a 2
§ 1 · = 6
a
¨ ¸
© a ¹
2
§ 1 · =6 (take square on both sides)
2
a
¨ ¸
© a ¹
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CITS: WCS - इले कल - अ ास 4