UP BOARD MATHS 2026: PHASE 3 (Q7 & Q8)

[Weightage: 16 Marks | Long Answer Mastery Zone]

QUESTION 7: MATRICES & LINEAR EQUATIONS 08 MARKS

Setter's Radar: Bhai, yahan Board 100% predictible haiред Q7 mein humesha "Matrix Method" ya "Inverse Proof" ka muqabla hota hai [cite: 1013, 2772, 5321]ред
Option A: Matrix Equation & Inverse Proof
Prove equation: \( A^3 - 6A^2 + 5A + 11I = 0 \) and then find \( A^{-1} \) using it [cite: 7123-7126, 8336]ред
рдЕрдерд╡рд╛ (OR)
Option B: Solve System of Equations (Matrix Method)
Solve for \( x, y, z \):
\[ 3x - 2y + 3z = 8 \] \[ 2x + y - z = 1 \] \[ 4x - 3y + 2z = 4 \]
[cite: 1013, 2772, 3187, 7132, 7552, 8348]
Topper Strategy for Q7: "Option B" (Matrix Method) humesha choose karoред Iske steps fixed hain aur calculation lambi hone par bhi logic clear hota haiред Bass \( \text{Det}(A) \neq 0 \) dikhana mat bhoolna!

QUESTION 8: AOD & DEFINITE INTEGRALS 08 MARKS

Expert Analysis: Q8 Board ka high-level logic zone haiред Isme aksar Applications of Derivatives aur Integral Properties ka combination hota haiред
Option A: Theoretical Optimization (AOD)
Prove: Maximum Volume of a cylinder/cone inscribed in a sphere of radius \( R \) is \( \frac{8}{27} \) of volume of sphere [cite: 1449, 3612, 5353, 5806, 7561, 8371]ред
рдЕрдерд╡рд╛ (OR)
Option B: Definite Integral Proofs (Property 4)
Prove:
\[ \int_{0}^{\pi} \frac{x \sin x}{1 + \cos^2 x} dx = \frac{\pi^2}{4} \]
Ya fir \( \int_{0}^{\pi/2} \log \sin x \, dx = -\frac{\pi}{2} \log 2 \) [cite: 1024, 1470, 2307, 2732, 3709, 4321, 5808, 6287, 7172, 8358]ред
Setter's Tip for Q8: AOD proof karte waqt diagram zaroor banayeinред Integral proofs mein property ka reference (рдЬреИрд╕реЗ: \( \int_0^a f(x) dx = \int_0^a f(a-x) dx \)) side mein bracket mein zaroor likheinред

MISSION 2026: FINAL WORD

Question 7 рдФрд░ 8 рдХреЗ рдпреЗ 16 рдирдВрдмрд░ рддреБрдореНрд╣рд╛рд░реА рдореЗрд░рд┐рдЯ рдбрд┐рд╕рд╛рдЗрдб рдХрд░реЗрдВрдЧреЗред "Matrix Method" рдФрд░ "Definite Integral Property 4" рдХреЛ рдХрдо рд╕реЗ рдХрдо 5-5 рдмрд╛рд░ рд╣рд▓ рдХрд░ рд▓реЛред рдмреЛрд░реНрдб рдПрдЧреНрдЬрд╛рдорд┐рдирд░ рдЗрди рд╕рд╡рд╛рд▓реЛрдВ рдХреЛ рдвреВрдВрдв-рдвреВрдВрдв рдХрд░ рдкреЗрдкрд░ рдореЗрдВ рдбрд╛рд▓рддрд╛ рд╣реИ!