Photomath is a good one. So is KhanAcademy, but I don't know if they have an app version of the website.
The value of cos A is √(1 + x²)/ (1 - x²) /√1 + x
<h3>Trigonometric ratios</h3>
It is important to note that
sin A = opposite/ hypotenuse
cos A = adjacent/ hypotenuse
Then,
opposite = 
Hypotenuse = 
Let's find the adjacent side using the Pythagorean theroem



cos A = x/hypotenuse

cos A = √(1 + x²)/ (1 - x²) /√1 + x
Thus, the value of cos A is √(1 + x²)/ (1 - x²) /√1 + x
Learn more about trigonometric identities here:
brainly.com/question/7331447
#SPJ1
Use this version of the Law of Cosines to find side b:
b^2 = a^2 + c^2 − 2ac cos(B)
We want side b.
b^2 = (41)^2 + (20)^2 - 2(41)(20)cos(36°)
After finding b, you can use the Law of Sines to find angles A and C or use other forms of the Law of Cosines to find angles A and C.
Try it....
Answer:
$41.11
Step-by-step explanation:
28.75 + (28.75 x 0.35) + (28.75 x 0.08)
Please mark brainliest and have a nice day
Full answer is 41.1125