4 hours subtract 4 from 6 and add 2 and their you go
1. Consider the tree diagram in the picture attached.
2 Each of the games picked can be a W (win) or a L (lose), the chances are equal
3. All that could happen in 4 picked games is shown in the picture:
2 w 2 l can happen in the following 6 ways: {(W,W,L,L)(W,L,W,L)(W,L,L,W)(L,W,W,L)(L,W,L,W)(L,L,W,W)}
4. P(2W,2L)=6/16=3/8
Ok,First Doing2/2=1 and After
2+1=3
X is in the second quadrant means that x/2 is in the first quadrant.
Consider the right triangle drawn in the figure. Let tan(x/2)=a.
Then, let the length of the opposite side to x/2 be a, the adjacent side be 1 and the hypotenuse be square root of a squared +1, as shown in the figure.
sin(x/2)=|opp side|/ |hypotenuse| =

cos (x/2) = |adj side|/ |hypotenuse| =

from the famous identity: sin(2a)=2sin(a)cos(a), we have:
2sin(x/2)cos (x/2)=sin(x)
thus




(3a-1)(a-3)=0
thus a=1/3 or a=3
thus tan(x/2)=1/3 or tan(x/2)=3
Answer: {1/3, 3}