MathematicsVariable Separable MethodJEE Advanced 2006Difficult
Visualized Solution (Hindi)
Analysis of Part (A): The Integral
- Let f(x)=(sinx)cosx
- Differentiating using dxd(uv)=uv[uvu′+v′logu]:
- dxd(sinx)cosx=(sinx)cosx[cosxcotx−sinxlog(sinx)]
- Notice that log(sinx)sinx=sinxlog(sinx)
- Thus, the integrand is exactly dxd(sinx)cosx
Evaluating Part (A)
- I=[(sinx)cosx]02π
- Evaluate at upper limit: (sin2π)cos2π=10=1
- Evaluate at lower limit: (sin0)cos0=01=0
- Result: 1−0=1
- (A) matches (p)
Part (B): Intersecting Parabolas
- Curves: x=−4y2 and x=1−5y2
- To find intersection, set x1=x2:
- −4y2=1−5y2
- y2=1⇒y=±1
- Intersection points are (−4,1) and (−4,−1)
Part (B): Area Calculation
- Area =∫−11(xright−xleft)dy
- Area =∫−11(1−5y2−(−4y2))dy
- Area =∫−11(1−y2)dy
- Area =[y−3y3]−11=(1−31)−(−1+31)=32+32=34
- (B) matches (s)
Part (C): Intersection of Curves
- Curves: y1=3x−1logx and y2=xx−1
- Intersection at x=1: y1(1)=0,y2(1)=0
- Slope m1=dxdy1=3x−1⋅x1+logx⋅3x−1ln3
- At x=1,m1=1
- Slope m2=dxdy2=xx(1+lnx). At x=1,m2=1
- Angle θ=0⇒cosθ=1
- (C) matches (p)
Part (D): Differential Equation Substitution
- Equation: dxdy=x+y6
- Let x+y=v⇒1+dxdy=dxdv
- Substitute: dxdv−1=v6
- dxdv=vv+6
Part (D): Solving and Final Answer
- Separate variables: ∫v+6vdv=∫dx
- ∫(1−v+66)dv=x+c
- v−6ln(v+6)=x+c
- Substitute v=x+y: y−6ln(x+y+6)=c
- Using (0,0): 0−6ln6=c⇒c=−6ln6
- When x+y=6: y−6ln(12)=−6ln6
- y=6(ln12−ln6)=6ln2
- (D) matches (r)
00:00 / 00:00
Conceptually Similar Problems
MathematicsFundamental Theorem & Properties of Definite IntegralsJEE Advanced 2007Easy
MathematicsVector (Cross) ProductJEE Advanced 2014Difficult
MathematicsEquation of a PlaneJEE Advanced 2006Difficult
MathematicsArea Bounded by CurvesJEE Advanced 2008Moderate
MathematicsFundamental Theorem & Properties of Definite IntegralsJEE Advanced 2010Difficult
MathematicsLinear Differential EquationsJEE Advanced 2009Difficult
MathematicsFundamental Theorem & Properties of Definite IntegralsJEE Advanced 1984Easy
MathematicsComponents of a VectorJEE Advanced 2015Difficult
MathematicsFundamental Theorem & Properties of Definite IntegralsJEE Advanced 1995Moderate
MathematicsArea Bounded by CurvesJEE Advanced 2002Easy