If we draw a rhombus OABC on a coordinate grid with one vertex at the point O (0,0)
and let its height be 1 then (using the Pythagoras theorem) the coordinates of the 4 points will be as follows:-
O = (0,0) , A = (1, 1), B = (sqrt2+ 1 , 1) , C = (sqrt2, 0)
Slope of the diagonal OB = 1 / (sqrt2 + 1)
Slope of the other diagonal AC = - 1 / (sqrt2 - 1)
Product of the slopes = - 1 / ( sqrt2 + 1)(sqrt2 - 1) = -1 / 1 = -1
This proves that the diagonals are perpendicular.
The answer to the question is -9n - 6
See, to make a 5-letter word , 5 places are to be filled ___ ___ ___ ___ ___ 1st 2nd 3rd 4th 5th the first place can be filled in 5 ways (s,p,e,l,l) 2nd place in 4 ways. 3rd place in 3 ways. 4th place in 2 ways. 5th place in 1 way. now , ther are 2L's. hence total no. of words that can be formed=(5*4*3*2*1) / 2*1
The answer is C.<span>consistent and independent</span>
Root root 20^2 - 4^2
X = 2
