Answer:
2kg
Step-by-step explanation:
Let the sum of the other 2 bricks be R. Given that the heaviest brick weighs 2/3 times as much as the other 2 bricks in total, then the weight of the heaviest brick H in terms of the weight of the other 2 will be
H = 2/3 * R
= 2R/3
Given that the 3 bricks weigh 5kg in total then,
2R/3 + R = 5
Multiply through the equation by 3
2R + 3R = 15
5R = 15
Divide both sides by 5
R = 15/5
= 3
The weight of the heaviest brick is 2R/3. Since R = 3, the heaviest block weighs
= 2 * 3/3
= 2kg
Lying in the same straight line i think..
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.
