Question

Consider the following statements :
Statement I : If the line segment joining the points P(m, n) and Q(r. s) subtends an angle `alpha` at the origin, then `cos alpha =(ms-nr)/sqrt((m^(2)+n^(2))(r^(2)+s^(2)))`.
Statements II : In any triangle ABC, it is true that `a^(2)=b^(2)+c^(2)-2bc cos A`.
What of the following is correct in respect of the above two statements ?
A. Both Statement I and Statement II are true and Statement II is the correct explanation of Statement I
B. Both Statement I and Statement II are true, but Statement II is not the correct explanation of statement I
C. Statement I is true, but Statement II is false
D. Statement I is false, but Statement II is true

Answer 1

Correct Answer - D
`cos alpha =(mr+ns)/(sqrt(m^(2)+n^(2)) sqrt(r^(2)+s^(2)))`
Statement 1 is false, statement 2 is true.