Q27) i think the options given are a bit incorrect
This should be the answer
Once confirm this answer from the solution given at the back , because sometimes in cengage the option are given wrong but solution is correct . Here in option A they have written OSA and there is no explanation to what S is , and if S is neglected then option A and B will be same , so i think maybe there was some printing error
Yes sir it is correct
Sir for ques 28 can we say that two parts are congruent then they are of same area. Sir I did this by area under curve
For 6.14 How can you be confirmed that it is A standard ellipse . What you have done is just shifting of the centre in the standard ellipse equation . But its not necessary that ellipse is perfectly horizontal. It can be slanted too.