Choice (a) if the question can be answered by using one of the statements alone, but cannot be answered by using the other statement alone.
Choice (b) if the question can be answered by using either statement alone.
Choice (c) if the question can be answered by using both the statements together, but cannot beanswered by using either statement alone.
Choice (d) if the question cannot be answered even by using both the statements together.

Is x+y> √2 ? (The square root of 2)

1)x^2 + y^2 =1

2)x= log a base b and y =log b base a ,where a,b,x,y are positive real number and a & b is not equal is 1

• Answer: B
  Solution in 2 parts.
  1. http://postimg.org/image/d7rx8ndox/
  2. http://postimg.org/image/y3e7jw9w1/
• 9 years agoHelpfull: Yes(8) No(3)
• Answer. C
  1. x+y= √ (x^2 + y^2 + 2.x.y) . We can get x^2 + y^2 from ....(1) But to get x.y we have to use ....(2)
  2. x=1/y (logarithm base rule) => x.y=1
  
  So from (1) and (2) we get [ x+y = √3 ] > √2
• 9 years agoHelpfull: Yes(7) No(2)
• sqrt((x+y)^2)=x+y
  =>sqrt(x^2+y^2+2xy)=x+y
  =>sqrt(1+2xy)=x+y
  from question:
  x=1/y (log a base b= (1/log b base a))
  =>sqrt(1+2)=x+y
  x+y=sqrt(3)
  => Option C
• 8 years agoHelpfull: Yes(3) No(0)
• here is Q. Url--> http://postimg.org/image/xzs2a0kqh/
• 9 years agoHelpfull: Yes(2) No(1)
• we cant use the both statements together because if x=1/y the x^2 + y^2 which is x^2 + (1/x)^2 is always greater than 2 hence can't be 1.
  
  So only the statement 2 can give that x + y >sqrt(2)
• 5 years agoHelpfull: Yes(0) No(0)