Using the dot product:
For any vector x, we have
||x|| = √(x • x)
This means that
||w|| = √(w • w)
… = √((u + z) • (u + z))
… = √((u • u) + (u • z) + (z • u) + (z • z))
… = √(||u||² + 2 (u • z) + ||z||²)
We have
u = ⟨2, 12⟩ ⇒ ||u|| = √(2² + 12²) = 2√37
z = ⟨-7, 5⟩ ⇒ ||z|| = √((-7)² + 5²) = √74
u • z = ⟨2, 12⟩ • ⟨-7, 5⟩ = -14 + 60 = 46
and so
||w|| = √((2√37)² + 2•46 + (√74)²)
… = √(4•37 + 2•46 + 74)
… = √314 ≈ 17.720
Alternatively, without mentioning the dot product,
w = u + z = ⟨2, 12⟩ + ⟨-7, 5⟩ = ⟨-5, 17⟩
and so
||w|| = √((-5)² + 17²) = √314 ≈ 17.720
Tuition is the price of attending classes at a school. Your welcome.
X1=2-Square root 5 x2=2+ Square root 5
The Pythagorean Theorem formula is listed below. It can only be applied to right triangles.
(side1)^2 + (side2)^2 = (hypotenuse)^2
Since we are given that the base is 8cm, we know that the side of one triangle is 4cm. We are also given that the hypotenuse is 8cm. The height of the cone will be one of the short sides. If we plug these numbers into the formula, we get the following...
4^2 + height^2 = 8^2
If we solve for height, we get the following...
height = sqrt(8^2 - 4^2) = sqrt(64 - 16) = sqrt(48)
Since we are only asked for what is inside the square root, our answer is 48.
This is a very good question to know about. People who make tests really like it.
The way to solve it is to make the slower car stop and use the difference in speed = to the rate. then do it as an ordinary d = r*t problem.
The difference in speeds is 44 - 36 = 8 miles/ hour.
d = 260 miles
r = 8 mph
t = ???
t = d/r
t = 260/8
t = 32.5 hours.
Thats 32 1/2 hours.
