Answer:
cos(71)
Step-by-step explanation:
Since 19° is less than 90, we can express this in terms of confunction.
sin(θ) = cos(90-θ)
sin(19) = cos(90-19)
sin(19) = cos(71)
There are 5 solutions for this system.
x^2 + 4y^2 = 100 ____1
4y - x^2 = -20 ____2
Add both 1 & 2 together. x^2 gets cancelled
4y^2 + 4y = 80 (send 80 to the other side and divide by 4)
Then equation the becomes : y^2 + y -20 =0
Now factorise the equation: (y+5) (y-4) = 0
Solve for y : y = -5 and y = 4
Using the values of y to find the values of x. From equation 1:
x^2 = 100 - 4y^2 x = /100 - 4y^2 (/ means square root) Replace values of y
y = -5, x = /100 - 4(-5)^2 = /100 - 100 = 0
y = 4, x = /100 - 4(4)^2 = / 100 - 64 = /36 = -6 or 6
Thus we have 6 solutions y = -5, 4 and x = -6, 0, 6
Answer:
x < -5
Step-by-step explanation:
- 2x - 7 > x+ 8
Add 2x to each side
- 2x+2x - 7 > x+2x+ 8
-7 > 3x+8
Subtract 8 from each side
-7-8 > 3x+8-8
-15 > 3x
Divide by 3
-15/3 > 3x/3
-5 >x
x < -5
The margin of error given the proportion can be found using the formula
Where
is the z-score of the confidence level
is the sample proportion
is the sample size
We have
Plugging these values into the formula, we have:
The result 0.14 as percentage is 14%
Margin error is 38% ⁺/₋ 14%
Answer:
See below.
Step-by-step explanation:
This is how you prove it.
<B and <F are given as congruent.
This is 1 pair of congruent angles for triangles ABC and GFE.
<DEC and <DCE are given as congruent.
Using vertical angles and substitution of transitivity of congruence of angles, show that angles ACB and GEF are congruent.
This is 1 pair of congruent angles for triangles ABC and GFE.
Now you need another side to do either AAS or ASA.
Look at triangle DCE. Using the fact that angles DEC and DCE are congruent, opposite sides are congruent, so segments DC and DE are congruent. You are told segments DF and BD are congruent. Using segment addition postulate and substitution, show that segments CB and EF are congruent.
Now you have 1 pair of included sides congruent ABC and GFE.
Now using ASA, you prove triangles ABC and GFE congruent.
