Home
Class 11
MATHS
Given that y=(3x-1)^(2)+(2x-1)^(3), find...

Given that `y=(3x-1)^(2)+(2x-1)^(3)`, find `(dy)/(dx)` and points on the curve for which `(dy)/(dx)=0`.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the derivative of the function \( y = (3x - 1)^2 + (2x - 1)^3 \) and then determine the points on the curve where this derivative equals zero. ### Step 1: Differentiate \( y \) with respect to \( x \) We start with the function: \[ y = (3x - 1)^2 + (2x - 1)^3 \] To find \( \frac{dy}{dx} \), we will use the chain rule and the power rule. 1. Differentiate \( (3x - 1)^2 \): \[ \frac{d}{dx}[(3x - 1)^2] = 2(3x - 1) \cdot \frac{d}{dx}(3x - 1) = 2(3x - 1) \cdot 3 = 6(3x - 1) \] 2. Differentiate \( (2x - 1)^3 \): \[ \frac{d}{dx}[(2x - 1)^3] = 3(2x - 1)^2 \cdot \frac{d}{dx}(2x - 1) = 3(2x - 1)^2 \cdot 2 = 6(2x - 1)^2 \] Now, we can combine these results: \[ \frac{dy}{dx} = 6(3x - 1) + 6(2x - 1)^2 \] ### Step 2: Factor out common terms We can factor out the common factor of 6: \[ \frac{dy}{dx} = 6 \left( (3x - 1) + (2x - 1)^2 \right) \] ### Step 3: Set \( \frac{dy}{dx} = 0 \) To find the points where the derivative is zero, we set: \[ 6 \left( (3x - 1) + (2x - 1)^2 \right) = 0 \] This simplifies to: \[ (3x - 1) + (2x - 1)^2 = 0 \] ### Step 4: Solve for \( x \) Now we need to solve the equation: \[ (3x - 1) + (2x - 1)^2 = 0 \] First, expand \( (2x - 1)^2 \): \[ (2x - 1)^2 = 4x^2 - 4x + 1 \] Substituting this back into the equation gives: \[ 3x - 1 + 4x^2 - 4x + 1 = 0 \] \[ 4x^2 - x = 0 \] Factoring out \( x \): \[ x(4x - 1) = 0 \] This gives us two solutions: 1. \( x = 0 \) 2. \( 4x - 1 = 0 \) which leads to \( x = \frac{1}{4} \) ### Step 5: Find corresponding \( y \) values Now we need to find the corresponding \( y \) values for \( x = 0 \) and \( x = \frac{1}{4} \). 1. For \( x = 0 \): \[ y = (3(0) - 1)^2 + (2(0) - 1)^3 = (-1)^2 + (-1)^3 = 1 - 1 = 0 \] So, the point is \( (0, 0) \). 2. For \( x = \frac{1}{4} \): \[ y = \left(3 \cdot \frac{1}{4} - 1\right)^2 + \left(2 \cdot \frac{1}{4} - 1\right)^3 \] \[ = \left(\frac{3}{4} - 1\right)^2 + \left(\frac{1}{2} - 1\right)^3 \] \[ = \left(-\frac{1}{4}\right)^2 + \left(-\frac{1}{2}\right)^3 = \frac{1}{16} - \frac{1}{8} = \frac{1}{16} - \frac{2}{16} = -\frac{1}{16} \] So, the point is \( \left(\frac{1}{4}, -\frac{1}{16}\right) \). ### Final Answer The points on the curve for which \( \frac{dy}{dx} = 0 \) are: 1. \( (0, 0) \) 2. \( \left(\frac{1}{4}, -\frac{1}{16}\right) \)
Promotional Banner

Topper's Solved these Questions

  • MODEL TEST PAPER - 10

    ICSE|Exercise SECTION - B (In sub-parts (i) and (ii) choose the correct option and in sub - parts (iii) to (v), answer the questions as instructed.)|5 Videos
  • MODEL TEST PAPER - 10

    ICSE|Exercise SECTION - B |5 Videos
  • MODEL TEST PAPER - 10

    ICSE|Exercise SECTION - C |5 Videos
  • MODEL TEST PAPER - 18

    ICSE|Exercise SECTION - C|9 Videos
  • MODEL TEST PAPER - 17

    ICSE|Exercise SECTION -C|10 Videos

Similar Questions

Explore conceptually related problems

Given that y= (3x -1)^(2) + (2x -1)^(3) , find (dy)/( dx) and the points on the curve for which (dy)/(dx)=0

y=x^(3/2) find dy/dx

y=x^(2)+(1)/(x^(2)) . Find (dy)/(dx)

If y=[(x^2+1)/(x+1)] , then find (dy)/(dx) .

y=x+x^(2)+(1)/(x)+(1)/(x^(3)) . Find (dy)/(dx)

y=(x^2+1/x^2)^3 find dy/dx

If y=(x+1)(x+2)^2(x+3)^3 , Find dy/dx

y=x(x+1)^3 find dy/dx

y=(5x)^(3cos 2x) then find (dy)/(dx) .

If y= (x^2 +3)/( x^3 + 2x) , find (dy)/( dx) at x=1 .

ICSE-MODEL TEST PAPER - 10 -SECTION - A
  1. Find the domain and range of f(x)=(x+2)/(|x+2|).

    Text Solution

    |

  2. List all the proper subsets of {0,{1},3}.

    Text Solution

    |

  3. If a cosA=b cos B, then prove that either the triangle is isosceles or...

    Text Solution

    |

  4. If secx=sqrt(2) and x does not lie in the 1^(st) quadrant, find the va...

    Text Solution

    |

  5. Solve 4cos^(2)x=3,0lexle2pi

    Text Solution

    |

  6. For the quadratic equation (k-1)x^(2)-kx+1=0, find k so that the roots...

    Text Solution

    |

  7. Find the greatest value of 3+5x-2x^(2).

    Text Solution

    |

  8. A function f is defined on the set of real numbers as follows : f(x)...

    Text Solution

    |

  9. If "tan"(x-y)/(2)," tan z, tan"(x+y)/(2) are in G.P., then show that c...

    Text Solution

    |

  10. If alpha and beta are two different values of theta lying between 0 an...

    Text Solution

    |

  11. Using principle of mathematical induction, prove that 5^(n+1)+4.6^(n) ...

    Text Solution

    |

  12. Given that y=(3x-1)^(2)+(2x-1)^(3), find (dy)/(dx) and points on the c...

    Text Solution

    |

  13. Differentiate using 1^(st) principle : f(x)=(1)/(sqrt(2x+3))

    Text Solution

    |

  14. If "tan"(x-y)/(2),tanz,"tan"(x+y)/(2) are in G.P., then show that cosx...

    Text Solution

    |

  15. If the A.M. and G.M. between two numbers are in the ratio x:y, then pr...

    Text Solution

    |

  16. Prove that ((i-sqrt(3))/(i+sqrt(3)))^(100)+((i+sqrt(3))/(i-sqrt(3)))^(...

    Text Solution

    |

  17. The point P(-1,0) lies on the circle x^(2)+y^(2)-4x+8y+k=0. Find the r...

    Text Solution

    |

  18. A line is drawn through the point A(4,-1) and parallel to the line 3x-...

    Text Solution

    |

  19. Lives of LG and Samsung Microwaves that are currently popular were obs...

    Text Solution

    |