💡 Note: Clean valuation key formatted according to Telangana SCERT standards. Fits fully on a single A4 page.
PRINCIPLE OF EVALUATION / VALUATION KEY
Class: X | Subject: Mathematics
Slip Test – II
Max Marks: 20
SECTION I (1 × 6 = 6 Marks)
Q1. Construct Similar Triangle (ΔA'BC' ~ ΔABC with scale factor 3/5) [AS 5 - Visualization & Representation]
[ Marks: 6 ]
| Rough Diagram & Given Data (AB = 5.6 cm, BC = 7.2 cm, CA = 4.8 cm) | 1.0 M |
| Constructing base BC = 7.2 cm, arcs for BA = 5.6 cm and CA = 4.8 cm to complete ΔABC | 1.5 M |
| Drawing acute ray BX and marking 5 equal divisions B1, B2, B3, B4, B5 | 1.5 M |
| Joining B5C and drawing B3C' ∥ B5C (C' on BC); then C'A' ∥ CA (A' on AB) | 1.5 M |
| Concluding ΔA'BC' is the required similar triangle | 0.5 M |
Q2. Prove sin θ = (P2 − 1) / (P2 + 1) given sec θ + tan θ = P [AS 2 - Reasoning & Proof]
[ Marks: 6 ]
| Using sec2θ − tan2θ = 1 ⇨ (sec θ + tan θ)(sec θ − tan θ) = 1 ⇨ sec θ − tan θ = 1/P | 1.5 M |
| Adding equations: 2 sec θ = P + (1/P) = (P2 + 1)/P ⇨ sec θ = (P2 + 1)/(2P) | 1.5 M |
| Subtracting equations: 2 tan θ = P − (1/P) = (P2 − 1)/P ⇨ tan θ = (P2 − 1)/(2P) | 1.5 M |
| Dividing tan θ by sec θ: sin θ = tan θ / sec θ = (P2 − 1) / (P2 + 1) (Hence Proved) | 1.5 M |
SECTION II (2 × 4 = 8 Marks)
Q3. Graph of p(x) = x2 + 2x − 3 and its zeros [AS 5 - Visualization & Representation]
[ Marks: 4 ]
| Table of values: x = [-4, -3, -2, -1, 0, 1, 2] ⇨ y = [5, 0, -3, -4, -3, 0, 5] | 1.0 M |
| Plotting points accurately on Cartesian plane with Scale (X: 1 cm = 1 unit, Y: 1 cm = 1 unit) | 1.5 M |
| Drawing parabolic curve intersecting X-axis at (-3, 0) and (1, 0) | 1.0 M |
| Conclusion: Zeros of the polynomial are x = -3 and x = 1 | 0.5 M |
Q4. In ΔABC, DE ∥ BC (AB = 14 cm, AD = 3.5 cm, AE = 2.5 cm). Find AC [AS 1 - Problem Solving]
[ Marks: 4 ]
| Applying Basic Proportionality Theorem (BPT): AD / AB = AE / AC | 1.0 M |
| Substituting given values: 3.5 / 14 = 2.5 / AC | 1.0 M |
| Simplifying ratio: 1 / 4 = 2.5 / AC ⇨ AC = 4 × 2.5 | 1.0 M |
| Final Answer: AC = 10 cm | 1.0 M |
SECTION III (3 × 2 = 6 Marks)
Q5. If p(x) = x4 + 1, find p(2) − p(-2) [AS 1 - Problem Solving]
[ Marks: 2 ]
| p(2) = (2)4 + 1 = 17 and p(-2) = (-2)4 + 1 = 17 | 1.0 M |
| p(2) − p(-2) = 17 − 17 = 0 | 1.0 M |
Q6. Express tan θ in terms of sin θ [AS 4 - Connections]
[ Marks: 2 ]
| Formulas: tan θ = sin θ / cos θ and cos θ = √(1 − sin2θ) | 1.0 M |
| Final Expression:
tan θ =
sin θ
√(1 − sin2θ)
|
1.0 M |
Q7. Pole height diagram (Distance = 15 m, Angle of elevation = 45°) [AS 5 - Visualization & Representation]
[ Marks: 2 ]
| Drawing right triangle ABC (AB = vertical pole, BC = ground = 15 m) | 1.0 M |
| Marking right angle at B and angle of elevation at C (∠ACB = 45°) | 1.0 M |
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