# Recent content by xiphoid

1. ### Trigonometry- addition and factor forumla

Homework Statement If tan(A+B) = 3 and tan(A-B) = 2, find tan2A and tan2B Homework Equations tan (A - B) = (tan A - tan B)/(1 + (tan A)(tan B) and similar sort of one for tan(A+B) The Attempt at a Solution i did some calculation and got tanA= (1-2tanB)/5tanB after which there...

Got it.
3. ### Bombing from an aeroplane

Then what about the theory part, I can only imagine those situations- to convert them into paper is somewhat difficult
4. ### Bombing from an aeroplane

Homework Statement A bomb is dropped from a plane flying horizontally with uniform speed. Show that the bomb will explode vertically below the plane. Is the statement true if the plane flies with uniform speed but not horizontally? Homework Equations Equations of projectile perhaps...
5. ### Chemistry Mole concept

Homework Statement On boiling 1litre of N/5 HCl, the volume of the aqueous solution decreases to 250ml. If 3.65g of HCl is removed from solution, then the concentration of resulting solution becomes? N/5 N/2.5 N/20 N/10 Homework Equations HCl=36.5g/ mol The Attempt at a Solution...
6. ### Biology Permutation and combination

Homework Statement A crew of an 8 oar boat has to be selected from 11 people, out of which 5 can oar only on one side, 4 can oar only on the other side and 2 can oar on either sides, find in how many ways can the selection be done? The Attempt at a Solution What I did here is assumed...
7. ### Permutation and combination

as per the answer given, you will need to consider both the cases!
8. ### Permutation and combination

Homework Statement how many 4 digit numbers are there which do not contain more than 2 different numbers? Homework Equations The Attempt at a Solution all can contain the same digit any 3 out of the 4 places can be occupied by the same digit and any 2 out of the 4 places can...
9. ### Permutation and combination

Homework Statement There are 15 players, out of which 4 players own one 4 seater car each, and the car will be driven by the owner himself. In how many ways can they be seated in the cars? Homework Equations (3n)!/(n!)3 The Attempt at a Solution i know that i have to substitute...
10. ### Indicate no of sigma and pi bonds

Homework Statement find total sigma and pi bonds in c6h6 Homework Equations Benzene structure The Attempt at a Solution if i consider benzene structure, then total will be 12σ and 3∏ but according to the random structure that i managed to draw, it showed, 11σ and 4∏, was i wrong...