I'll explain how to do the first one:-
y = cos-1(x2)
This can be described as ' a function of a function' x^2 is a function of x and cos-1(x^2) is a function of x^2.
We need to apply the chain rule.
Personally I find this easier to understand if i let u = x^2, so
If y = f(u) and u is a function of x then
dy/dx = dy/ du * du/dx
Here u = x^2 and y = cos-1(u)
du/dx = 2x
so dy/dx = d(cos-1(x^2) dx = dy/du * du/dx
= -1 / √(1 - u^2) * 2x
= -2x / √(1 - u^2)
= -2x / √(1 - (x^2)^2)
= -2x / √(1 - x^4)
I hope this helps. but if not. you might like to employ the formulae in the question - The square boxes contain the 'u' s in my answer. These formulae are equivalent to my explanation.
answer: -5x+12=20
-12 -12
-5x/-5= 8/-5
x= -1.6
Check: rewrite the orignal problem
plug your variable
Answer:
25%
Step-by-step explanation:
117/3 = 39
39 + 39 + 39 = 177
They must be consecutive.
The integers are 37, 39, and 41.
Law of cosine:
c² = a² +b² -2ab*cosC.
Because the triangle is equilateral a=b=c=x,
and we can write,
x²=x² +x² -2xx*cosC
x² =2x² -2x²* cos C
-x² = -2x²*cos C
cos C= 1/2,
so m∠C=60⁰.
Because all sides are equal, and across of the equal sides should be equal angles, all angles will be also equal and = 60⁰.
