Mathematics - Online Test

Q1. Position vectors of points A, B, C, etc., with respect to the origin O are generally denoted by
Answer : Option B
Explaination / Solution:

Position vectors of any point in space are usually calculated from the origin, so we  write  three points A ,B,C  in space to represent the origin as the initial point.

Q2. A coin is tossed three times, E : at most two tails , F : at least one tail. Find P(E|F)
Answer : Option C
Explaination / Solution:



Q3. The maximum value of sin x + cos x is
Answer : Option D
Explaination / Solution:

(12)+(12)=2
Q4. is equal to
Answer : Option B
Explaination / Solution:

   
Q5. If x  -1 , then the statement  is true for
Answer : Option D
Explaination / Solution:

For example , if x = 0 and n > 1 , say n = 2 then the given inequality will become 12 > 1 , which is not true. Hence both the conditions on x and n are needed.

Q6. The number of triangles that can be formed with 6 points on a circle is
Answer : Option D
Explaination / Solution:

To form a triangle 3 non collinear points are needed.

Number of ways of selecting 3  points out of 6 can be  done in 6C3 = 20 ways.   



Q7. The circles  and 
Answer : Option B
Explaination / Solution:

Circle touches externally if distance between the centers is equal to the sum of the radii .

After applying completing the square, we get

so the center is (-3,-3) and radius is 

After applying completing the square

so the center is (6,6) and radius is 
Distance between centres  and sum of radii   are equal.

Hence the circle touches externally.



Q8. Degree of a differential equation, when the equation is polynomial equation in y′ is
Answer : Option B
Explaination / Solution:

The power or index of the highest ordered derivative in the polynomial is the degree of the differential equation provided equation is in the standard form.

Q9.

 is a vector joining two points P(x1, y1, z1) and Q(x2, y2, z2).If ,Direction cosines of are


Answer : Option A
Explaination / Solution:

since we know Direction cosines of a line are coefficient of i,j,k of a unit vector along that line,first find a vector   then to convert  it unit vector divide by its magnitute || the coefficient of this unit vector will be 
Q10. If the sides of a triangle are 13, 7, 8 the greatest angle of the triangle is
Answer : Option C
Explaination / Solution:

Let the sides of the triangle be a=13,b=7 and c=8.

Since a  is the longest side the greatest angle is A.

Using Cosine rule, we have