<span>3-2(Cosx)^2 - 3Sinx = 0.
Recall (Sinx)^2 + (Cosx)^2 = 1.
Therefore (Cosx)^2 = 1 - (Sinx)^2
Substitute this into the question above.
</span><span>3-2(Cosx)^2 - 3Sinx = 0
3 - 2(1 - (Sinx)^2) - 3Sinx = 0 Expand
3 - 2 + 2(Sinx)^2 - </span><span><span>3Sinx = 0</span>
1 + 2(</span><span>Sinx)^2 - 3Sinx = 0 Rearrange
2(Sinx)^2 </span><span><span>- 3Sinx + </span>1 = 0
Let p = Sinx
2p^2 - 3p + 1 = 0 Factorise the quadratic expression
2p^2 - p - 2p +1 = 0
p(2p -1) - 1(2p -1) = 0
(2p-1)(p -1) = 0
Therefore 2p-1=0 or (p-1) = 0
2p=0+1 or (p-1) = 0
2p=1 or p = 0 +1.
p=1/2 or p = 1 Recall p = Sinx
Therefore Sinx = 1/2 or 1.
For 0<u><</u>x<u><</u>360
Sinx =1/2, x = Sin inverse (1/2) , x = 30,
(180-30)- 2nd Quadrant = 150 deg
Sinx = 1, x = Sin inverse (1) , x = 90
Therefore x = 30,90 & 150 degrees.
Cheers.</span>
I think its the first and fourth tv
Answer:
The length of DF must be between 21 and 53.
Step-by-step explanation:
In a triangle, the length of two sides added together must exceed the length of the 3rd side. So, since EF is the shortest of the two givens, we know that EF + DF must be greater than DE. So we can plug in these numbers to find the minimum.
EF + DF > DE
16 + DF > 37
DF > 21
Now, for the upper maximum, we know that the two given lengths must be greater than the length of DF. So again, we can solve for the maximum using the amounts.
DE + EF > DF
37 + 16 > DF
53 > DF
With these two in mind, we know that DF must be between 21 and 53
Answer: (0,1)
Step-by-step explanation:
Hope this helps
Answer:
mmmm
Step-by-step explanation:
13.9 sounds correct, try it
