Only when <em>b</em> = 0 or <em>k</em> = 1<em>.</em>
If <em>f(x)</em> = <em>mx</em> + <em>b</em>, then
<em>f</em> (<em>kx</em>) = <em>m</em> (<em>kx</em>) + <em>b</em> = <em>mkx</em> + <em>b</em>
while
<em>k</em> <em>f(x)</em> = <em>k</em> (<em>mx</em> + <em>b</em>) = <em>kmx</em> + <em>kb</em>
The two expression are identical only if
<em>kb</em> = <em>b</em> ===> <em>kb</em> - <em>b</em> = 0 ===> <em>b</em> (<em>k</em> - 1) = 0 ===> <em>b</em> = 0 or <em>k</em> = 1
7/10 / 3/1
7/10 x 1/3
7/30
(not sure if this is correct)
The height of broken part of tree from ground is 5.569m.
Justification:
Let BD is a tree of height 12 m.
<u>Suppose it got bent at a point C and let the part CD take the position CA, meeting the ground at A</u>.
i.e., CD = AC = h m
<u>Broken part makes 60° angle from ground</u>
So, ∠BAC = 60°
<u>Now, height of remaining part of tree</u> = (12 – h)m.
In right angled ∆ABC,
sin 60° = BC/AC
⇒ √3/2 = (12 - h)/h
⇒ √3h = 2(12 – h)
⇒ √3h = 24 – 2h
⇒ √3h + 2h = 24
⇒ h(√3 + 2) = 24
⇒ h(1.732 + 2) = 24
⇒ h(3.732) = 24
⇒ h = 24/3.732 = 6.4308 m
<u>Hence, height of broken tree from ground</u>
⇒ BC = 12 – h
⇒ 12 – 6.4308 = 5.569m
<u>Hence, tree is broken 5.569 m from ground</u>.
<u>Note</u>: See attached picture.
Answer:
x = 1/4
y = -1/2
z = 9/4
Step-by-step explanation:
Here we have a system of 3 equations with 3 variables:
4*x + 2*y + 1 = 1
2*x - y = 1
x + 3*y + z = 1
The first step to solve this, is to isolate one of the variables in one of the equations, let's isolate "y" in the second equation:
2*x - y = 1
2*x - 1 = y
Now that we have an expression equivalent to "y", we can replace this in the other two equations:
4*x + 2*(2*x - 1) + 1 = 1
x + 3*(2*x - 1) + z = 1
Now let's simplify these two equations:
8*x - 1 = 1
7*x - 3 + z = 1
Now, in the first equation we have only the variable x, so we can solve that equation to find the value of x:
8*x - 1 = 1
8*x = 1 + 1 = 2
x = 2/8 = 1/4
Now that we know the value of x, we can replace this in the other equation to find the value of z.
7*(1/4) -3 + z = 1
7/4 - 3 + z = 1
z = 1 + 3 - 7/4
z = 4 - 7/4
z = 16/4 - 7/4 = 9/4
z = 9/4
Now we can use the equation y = 2*x - 1 and the value of x to find the value of y:
y = 2*(1/4) - 1
y = 2/4 - 1
y = 1/2 - 1
y = -1/2
Then the solution is:
x = 1/4
y = -1/2
z = 9/4
Answer:
5
Step-by-step explanation:
cos 60° = y / 10
y = 10 * 1/2 = 5
