3.62 I FUNDAMENTALS OF BUSINESS MATHEMATICS AND STATISTICS
Calculus
Example 126:If dxdy=x 3x 1^3 −^2 + and y = 2 when x = 1, find y.
or,
3 2 x x^43
y x dx 3 x dx dx= − + = 4 3−3 x c+ +
or,^2 = 41 − + +1 1 c or,^2 = 41 +cor, c 2= −^14 =7/ 4
∴
x^437
y= 4 −x x+ + 4
SELF EXMINATION QUESTIONS
- (i) x^11 (ii) x^410 (iii) x (iv) xa (v) a (vi) 2.
x^12 x^411 x^2 x 1a
Ans.(i) 12 (ii) 411 (iii) (iv)x a 1++ (v) ax (vi) 2x;+c in all the case^ - (i) x–11 (ii) x–n (iii) x^1 n (iv) x^12 (v)^1 x (vi) x–1
x^10 xn 1 xn 1 1
Ans.(i) 10 (ii) n 1 (iii) n 1 (iv) (v) and (vi) logxx
− − + − + −
(^) − − + − + (^)
- (i) x3/2 (ii) x^5
(^25) /2 3 4 5/2 x^2
(^) Ans.(i) x (ii)x x 5 + 5 + 2
Integrate :
- (i) x xdx (ii) ( )
2
x x dx
(^2) 5/2 3 4 5/2 x^2
(^) Ans. (i) x (ii) x x 5 + 5 + 2
- (i)
4 2
3
x 2x 1dx
x
+ +
(ii)
(x 3 )^2 dx
x
−
(iii)
( )
2
2 x 1
dx
x x
+
(^25) /2 3/2
2
Ans. (i) 2logxx^1 (ii) x 4x 18 x (iii) 4 x 4logx^24
2 2x (^5) x
(^) + − − + + −
(^)
- (i)
x 1^2
(^) x 1−− dx (ii)
x 1^3
(^) x 1−− dx (iii)
x 3x 2^2
+x 1+ + dx (iv)
x^2 x 6
(^) x 2− −+ dx.
x^2 x x^32 x^2 x^2
Ans. (i) x (ii) 2 + 3 2+ (iii) 2x (iv) 3x 2 + 2 −