<span>We are given that ||e|| = 1, ||f|| = 1. </span>
<span>Since ||e + f|| = sqrt(3/2), we have </span>
<span>3/2 = (e + f) dot (e + f) </span>
<span>= (e dot e) + 2(e dot f) + (f dot f) </span>
<span>= ||e||^2 + 2(e dot f) + ||f||^2 </span>
<span>= 1^2 + 2(e dot f) + 1^2 </span>
<span>= 2 + 2(e dot f). </span>
<span>So e dot f = -1/4. </span>
<span>Therefore, </span>
<span>||2e - 3f||^2 = (2e - 3f) dot (2e - 3f) </span>
<span>= 4(e dot e) - 12(e dot f) + 9(f dot f) </span>
<span>= 4||e||^2 - 12(e dot f) + 9||f||^2 </span>
<span>= 4(1)^2 - 12(-1/4) + 9(1)^2 </span>
<span>= 4 + 3 + 9 </span>
<span>= 16. </span>
Solution
- The number of possible outcomes in the sample space is simply gotten by multiplying out all the events together.
- There are 3 possible days: Tuesday, Wednesday, or Thursday. Thus, there are 3 possible outcomes.
- There are 3 possible times: 3PM, 4PM, or 5PM. Thus, there are 3 possible outcomes again.
- There are also 9 possible classrooms available meaning another 9 possible outcomes.
- Thus, the total possible outcomes in the sample space is
I think it can be C. but then again who am i
X and Y are supplementary, that means X + Y = 180.
But we have, X = Y +24, then
X + Y = Y + 24 + Y = 2Y + 24 = 180
Then
2Y = 156
Y = 78
Then X = 78 + 24 = 102.