We have: 4 for 1 leg. 22 for the hypotenuse. Use Pytago theory: the remain leg = sqrt ( 22^2 - 4^2 ) = sqrt ( 468). The area of the triangle is: 1/2 • leg 1 • leg 2. Area = 1/2 • 4 • sqrt(468) = 2sqrt(468). We need to find k in k•cos x. You dont say what angle is x. So I will give 3 cases. Let find 3 angles first. a = 90° b = tan^-1 [4 / sqrt(468)] c = tan^-1 [sqrt(468) / 4] With a: 2sqrt(468) = k cos(90°) cos 90° = 0, so in this case, it leads to an undefined case. With b: 2sqrt(468) = k cos(tan^-1 [4 / sqrt(468)]) <=> k = 44 Use regression or devide both sides by cos(...) to find k. With c: 2sqrt(468)= k cos(tan^-1 [sqrt(468) / 4]) <=> k = 237,9663841... So k = 44. Or k = 237,9663841...

@Nigel S I dont really use desmos for core parts, I just use it for calculation only. Because I don't know how to use it better in this case.

@Nigel S I found it: https://www.desmos.com/calculator/23lpkdzjyj From those experience, I have a very useful lesson for myself. Try to put as many correct equations as possible!

@Alan P yea sure 🤗

"The quality of the people here has really improved as the good people stayed, bad people left" feel sad

@Jason Parton Not about myself, Im thinking of others who left. They should be encouraged and helped so that they don't feel too tired and wanting to quit. The environment that helps people to continue through difficulties (despite of whoever they are) is more and certainly more important than an environment which is full of good people.

peak