Download App

STD 11 - 9. straight line — Maths STD 11 Science — Question

CBSE BoardEnglish MediumSTD 11 ScienceMathsSTD 11 - 9. straight line1 Mark
MCQ
The angle between the lines $2x - y + 3 = 0$ and $x + 2y + 3 = 0$ is ...........  $^\circ$
  • ✓
    $90$
  • B
    $60$
  • C
    $45$
  • D
    $30$
✓

Answer

Correct option: A.
$90$
a
(a)Angle between two lines is given by $\tan \theta = \frac{{{m_1} - {m_2}}}{{1 + {m_1}{m_2}}}$
Given ${m_1} = \frac{{ - 1}}{2},$ ${m_2} = 2$ $\therefore \,\,{m_1}{m_2} = - 1$.
So the lines are perpendicular i.e., $\theta = 90^\circ $.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from STD 11 - 9. straight line→STD 11 - 9. straight line — all question types→Maths STD 11 Science question papers→CBSE Board STD 11 Science question papers→CBSE Board question paper generator→

Similar questions

If $p$ then $q$ means if $p$ is $...........$ then $q$ must be $...........$
→
Find the $25^{th}$ common term of the following $A.P.'s$

$S_1 = 1, 6, 11, .....$

$S_2 = 3, 7, 11, .....$

→
If four vertices of a regular octagon are chosen at random, then the probability that the quadrilateral formed by them is a rectangle is
→
The number of words which can be made out of the letters of the word $MOBILE $when consonants always occupy odd places is
→
If $P(n): “49^n+ 16^n+ k$ is divisible by $64$ for $n \in N”$ is true, then the least negative integral value of $k$ is:
→
Fifth term of a $G.P.$ is $2$, then the product of its $9$ terms is
→
Let $C_i \equiv  x^2 + y^2 = i^2 (i = 1,2,3)$ are three circles. If there are $4i$ points on circumference of circle $C_i$. If no three of all the points on three circles are collinear then number of triangles which can be formed using these points whose circumcentre does not lie on origin, is-
→
Let $S=\left\{\theta \in[-\pi, \pi]-\left\{\pm \frac{\pi}{2}\right\}: \sin \theta \tan \theta+\tan \theta=\sin 2 \theta\right\} \text {. }$  If $T =\sum_{\theta \in S } \cos 2 \theta$, then $T + n ( S )$ is equal
→
Which one of the following is the common tangent to the ellipses, $\frac{{{x^2}}}{{{a^2} + {b^2}}} + \frac{{{y^2}}}{{{b^2}}}$ $=1\&$ $ \frac{{{x^2}}}{{{a^2}}} + \frac{{{y^2}}}{{{a^2} + {b^2}}}$ $=1$
→
The cube root of $9\sqrt 3 + 11\sqrt 2 $ is
→