Thoroughly analyzing AP Inter 1st Year Maths 1A Model Papers Set 1 helps students identify their strengths and weaknesses.

## AP Inter 1st Year Maths 1A Model Paper Set 1 with Solutions

Time: 3 Hours

Maximum Marks: 75

Note: The Question Paper consists of three sections A, B, and C.

Section – A

(10 × 2 = 20 Marks)

**I. Very Short Answer Questions.**

- Answer All Questions.
- Each Question Carries Two marks.

Question 1.

Find the range of the real-valued function \(\sqrt{[x]-x}\).

Question 2.

Let f = {(1, a), (2, c), (4, d), (3, b)} and g-1{(2, a), (4, b), (1, c), (3, d)} then show that (gof)^{-1} = f^{-1}og^{-1}.

Question 3.

Define the trace of a matrix.

Question 4.

If A = \(\left[\begin{array}{cc}

-2 & 1 \\

5 & 0 \\

-1 & 4

\end{array}\right]\) and B = \(\left[\begin{array}{ccc}

-2 & 3 & 1 \\

4 & 0 & 2

\end{array}\right]\) then find 2A + B^{T} and 3B^{T} – A.

Question 5.

ABCDE is a pentagon. If the sum of the vectors \(\overline{\mathrm{AB}}, \overline{\mathrm{AE}}, \overline{\mathrm{BC}}, \overline{\mathrm{DC}}, \overline{\mathrm{ED}}\) and \(\bar{AC}\) is λ(\(\bar{AC}\)), then find the value of λ.

Question 6.

\(\bar{a}, \bar{b}, \bar{c}\) are pair wise non-zero and non collinear vectors. If \(\bar{a}+\bar{b}\) is collinear with \(\bar{c}\) and \(\bar{b}+\bar{c}\) is collinear with \(\bar{a}\), then find the vector \(\bar{a}+\bar{b}+\bar{c}\).

Question 7.

Find the angle between the planes \(\overline{\mathrm{r}} \cdot(2 \overline{\mathrm{i}}-\overline{\mathrm{j}}+2 \overline{\mathrm{k}})=3\) and \(\bar{r} \cdot(3 \bar{i}+6 \bar{j}+\bar{k})=4\).

Question 8.

Prove that tan 50° – tan 40° = 2 tan 10°.

Question 9.

Find the value of cot \(67 \frac{1}{2}^{\circ}\).

Question 10.

For any n ∈ R, prove that (cosh x – sinh x)^{n} = cosh (nx) – sinh (nx).

Section – B

(5 × 4 = 20 Marks)

**II. Short Answer Questions.**

- Answer any Five questions.
- Each Question carries Four marks.

Question 11.

If I = \(\left[\begin{array}{ll}

1 & 0 \\

0 & 1

\end{array}\right]\) and E = \(\left[\begin{array}{ll}

0 & 1 \\

0 & 0

\end{array}\right]\) then show that (aI + bE)^{3} = a^{3}I + 3a^{2}bE.

Question 12.

The median AD of ∆ABC is bisected at E and BE is produced to meet the side AC in F. Show that \(\overline{\mathrm{AF}}=\frac{1}{3}(\overline{\mathrm{AC}})\) and \(\overline{\mathrm{EF}}=\frac{1}{4} \overline{\mathrm{BF}}\).

Question 13.

Let \(\overline{\mathrm{a}}=\overline{\mathrm{i}}+\overline{\mathrm{j}}+\overline{\mathrm{k}}\) and \(\overline{\mathrm{b}}=2 \overline{\mathrm{i}}+3 \overline{\mathrm{j}}+\overline{\mathrm{k}}\). Find

(i) The projection vector of \(\bar{b}\) on \(\bar{a}\) and its magnitude.

(ii) The component vector of \(\bar{b}\) in the direction of a and perpendicular to \(\bar{a}\).

Question 14.

If 8α is not an integral multiple of π, then prove that tan α + 2 tan 2α + 4 tan 4α + 8 cot 8α = cot α.

Question 15.

If \(\tan \left(\frac{\pi}{2} \sin \theta\right)=\cot \left(\frac{\pi}{2} \cos \theta\right)\), then prove that \(\sin \left(\theta+\frac{\pi}{4}\right)= \pm \frac{1}{\sqrt{2}}\).

Question 16.

Prove that \(\tan \left(\frac{\pi}{4}+\frac{1}{2} \cos ^{-1} \frac{a}{b}\right)+\tan \left(\frac{\pi}{4}-\frac{1}{2} \cos ^{-1} \frac{a}{b}\right)=\frac{2 b}{a}\).

Question 17.

In ∆ABC, prove that \(\left[\frac{b-c}{b+c}\right] \cot \left(\frac{A}{2}\right)+\frac{b+c}{b-c} \tan \left(\frac{A}{2}\right)\) = 2 cosec (B – C).

Section – C

(5 × 7 = 35 Marks)

**III. Long Answer Questions.**

- Answer any Five questions.
- Each question carries Seven marks.

Question 18.

If f = {(4, 5), (5, 6), (6, -4)} and g = {(4, -4), (6, 5), (8, 5)} then find

(i) f – g

(ii) fg

(iii) \(\frac{f}{g}\)

(iv) |f|

(v) 2f + 4g

Question 19.

Using mathematical induction, for all n ∈ N, prove that 2.3 + 3.4 + 4.5 + …… up to n terms = \(\frac{n\left(n^2+6 n+11\right)}{3}\).

Question 20.

Show that \(\left|\begin{array}{lll}

a & b & c \\

b & c & a \\

c & a & b

\end{array}\right|^2=\left|\begin{array}{ccc}

2 b c-a^2 & c^2 & b^2 \\

c^2 & 2 a c-b^2 & a^2 \\

b^2 & a^2 & 2 a b-c^2

\end{array}\right|\)

Question 21.

Solve the following system of equations by using the Gauss-Jordan method.

2x + 4y – z = 0, x + 2y + 2z = 5, 3x + 6y – 7z = 2.

Question 22.

Let \(\overline{\mathrm{OA}}=\overline{\mathrm{a}}, \overline{\mathrm{OB}}=10, \overline{\mathrm{a}}+2 \overline{\mathrm{b}}\) and \(\overline{\mathrm{OC}}=\overline{\mathrm{b}}\) where O, A, B and C are non-collinear points. Let λ denote the area of the quadrilateral OABC and Let µ denote the area of the parallelogram with \(\bar{OA}\) and \(\bar{OC}\) as adjacent sides. Prove that λ = 6µ.

Question 23.

In ΔABC, prove that \(\cos \frac{A}{2}+\cos \frac{B}{2}+\cos \frac{C}{2}=4 \cos \left(\frac{\pi-A}{4}\right) \cos \left(\frac{\pi-B}{4}\right)\) \(\cos \left(\frac{\pi-C}{4}\right)\).

Question 24.

If r_{1} = 36, r_{2} = 18 and r_{3} = 12, then prove that a = 30, b = 24, c = 18 and R = 15.