Design a circuit which takes two inputs and outputs a 1 if and only if the two inputs are the same signal. You may only use two 2-Input AND gates, one 2-Input OR gate and two NOT gates.[3]

Q = A ⊕ B = (A AND B) + ( not(A) AND not(B) )

Explanation:

AND gates : only output 1 when both inputs are 1

OR gate:  only output 1 when either or both of the inputs are 1

NOT gates: takes only one input ad output the opposite of the input

The required circuit should takes two inputs and outputs a 1 if and only if the two inputs are the same signal.

The two possible scenarios : both input are 1's or 0's

Q = A ⊕ B = (A AND B) + ( not(A) AND not(B) )

A  B  not(A) not(B)  A AND B    not(A) AND not(B)   Q

0  0     1          1            0                      1                       1

0   1      1         0            0                     0                       0

1    0     0        1             0                     0                       0

1     1     0       0              1                     0                       1

the working equation for the angular size is the product of the physical size and 360 degrees divided by the product of two pi and distance from earth. the minimum size would be 0.559 degrees while the maximum size would be 0.49 degrees.