Answer:
yes, you got it correct
Step-by-step explanation:
The answer is the third one
Answer:
In the given figure the point on segment PQ is twice as from P as from Q is. What is the point? Ans is (2,1).
Step-by-step explanation:
There is really no need to use any quadratics or roots.
( Consider the same problem on the plain number line first. )
How do you find the number between 2 and 5 which is twice as far from 2 as from 5?
You take their difference, which is 3. Now splitting this distance by ratio 2:1 means the first distance is two thirds, the second is one third, so we get
4=2+23(5−2)
It works completely the same with geometric points (using vector operations), just linear interpolation: Call the result R, then
R=P+23(Q−P)
so in your case we get
R=(0,−1)+23(3,3)=(2,1)
Why does this work for 2D-distances as well, even if there seem to be roots involved? Because vector length behaves linearly after all! (meaning |t⋅a⃗ |=t|a⃗ | for any positive scalar t)
Edit: We'll try to divide a distance s into parts a and b such that a is twice as long as b. So it's a=2b and we get
s=a+b=2b+b=3b
⇔b=13s⇒a=23s
From the two right triangles, you can write the following equations using the Pythagorean theorem. Let's call that shared leg in the middle "y"
y^2 + b^2 = a^2
y^2 + c^2 = x^2
y^2 + b^2 = a^2
re-write this to get "y" alone for substitution.
y^2 = a^2 - b^2
substitute (a^2 - b^2) for y^2 in the other equation. y^2 + c^2 = x^2
a^2 - b^2 + c^2 = x^2
Now put in the values given for a,b,c to solve for x
(7.1)^2 - (5.6)^2 + (5.7)^2 = x^2
51.54 = x^2
square root
7.2 = x
Answer:
a. 1,275.49 m²
Step-by-step explanation:
SA = 2πr² + 2πrh
SA = 2π(7)² + 2π(7)(22)
SA = 98π + 308π
SA = 406π
SA ≈ 1,275.49 m²
