Mathematics - Online Test

Q1. If , then the value of  
Answer : Option D
Explaination / Solution:



Q2. The area of triangle formed by the lines y = x, y = 2x and y = 3x + 4 is
Answer : Option A
Explaination / Solution:

Area of the triangle formed by the coordiates( x1,y1), (x2,y2) and (x3,y3) is given by

[x1(y- y3) + x2(y3 - y1) + x3(y- y2)]

On solving the lines 1 and 2, the point of intersection is (0,0)

On solving the lines 2 and 3, the point of intersection is (4,8)

\On solving the line 3 and 1 , the point of intersection is (-2,-2)

Now substituting the values to find the area of the triangle,

Area = | [ 0 + 4(-2-0) +(-2)(0 - 8)] |

 = 4 sq units


Q3. The contrapositive of (p∨q)→r is
Answer : Option D
Explaination / Solution:

the contrapositive of p→q is∼q→∼p

Q4. An antiderivative of  is equal to
Answer : Option C
Explaination / Solution:



Q5.

Find the values of x and y so that the vectors  are equal


Answer : Option C
Explaination / Solution:

  
x = 2, y = 3

Q6. If then x =
Answer : Option B
Explaination / Solution:




Q7. The locus of the point of intersection of the lines x cos α + y sin α=a and x sin α - y cos α = b is
Answer : Option D
Explaination / Solution:

Solving the above two equations we get,

---(i) 

 ---(ii)

Squaring both sides of (i) and (ii) and adding both the equation we get  x2+y2=a2+b2.

which represents the locus of circle as

(i) it is quadratic equation

(ii) coeff of x2 = coeff of y2

(iiI) there is no trerm involving xy.


Q8. If a function f is derivable at x = a, then is equal to
Answer : Option C
Explaination / Solution:



Q9. If the radius of the circumcircle of an isosceles triangle PQR is equal to PQ ( = PR), then the angle P is


Answer : Option A
Explaination / Solution:



Q10. 1.2.3 + 2.3.4 + 3.4.5 + ………..up to n terms is equal to 1/4 n ( n + 1 ) ( n + 2 ) ( n + 3 ) is true for


Answer : Option A
Explaination / Solution:

By the method of mathematical induction the given statement is true for n = 1,2,3.....