Matrices and Vectors
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Pre-Calculus › Matrices and Vectors
Find the dot product of the two vectors
and
.
Explanation
To find the dot product of two vectors,
find the product of the x-components,
find the product of the y-components,
and then find the sum.
Add:
Explanation
In order to add matrices, they have to be of the same dimension. In this case, they are both 2x2.
The formula to add matrices is as follows:
Plugging in our values to solve we get:
Find if
and
.
Explanation
To find the direction vector going from to
, subtract the x and y-coordinates of
from
.
Write this vector in component form:
Explanation
To figure out the horizontal component, set up an equation involving cosine, since that side of the implied triangle is adjacent to the 48-degree angle:
To solve for x, first find the cosine of 48, then multiply by 11:
To figure out the vertical component, set up an equation involving sine, since that side of the implied triangle is opposite the 48-degree angle:
to solve for y, just like x, first find the sine of 48, then multiply by 11:
Putting this in component form results in the vector
Find the component form of the vector with
initial point
and
terminal point .
Explanation
To find the vector in component form given the initial and terminal points, simply subtract the initial point from the terminal point.
Find , then find its magnitude.
and
are both vectors.
Explanation
In vector addition, you simply add each component of the vectors to each other.
x component: .
y component: .
z component: .
The new vector is
.
To find the magnitude we use the formula,
Thus its magnitude is 5.
Find the dot product of the two vectors
and
.
Explanation
To find the dot product of two vectors,
find the product of the x-components,
find the product of the y-components,
and then find the sum.
Write the parametric equation for the line y = -3x +1.5
x = -3t +1.5
y = -3t +1.5
x = t
y = 1.5t - 3
x = t
y = -3t +1.5
x = -3t +1.5
y = t
Explanation
In the equation y = -3x +1.5, x is the independent variable and y is the dependent variable. In a parametric equation, t is the independent variable, and x and y are both dependent variables.
Start by setting the independent variables x and t equal to one another, and then you can write two parametric equations in terms of t:
x = t
y = -3t +1.5
Write an equation in slope-intercept form of the line with the given parametric equations:
Explanation
Start by solving each parametric equation for t:
Next, write an equation involving the expressions for t; since both are equal to t, we can set them equal to one another:
Multiply both sides by the LCD, 6:
Get y by itself to represent this as an equation in slope-intercept (y = mx + b) form:
Find the parametric equations for a line parallel to and passing through the point (0, 5).
x = 5t
y = 3 + 2t
x = 3 + 2t
y = 5t
x = 3
y = 2 + 5t
x = 3t
y = 5 + 2t
Explanation
A line through a point (x1,y1) that is parallel to the vector = (a1, a2) has the following parametric equations, where t is any real number.
Using the given vector and point, we get the following:
x = 3t
y = 5 + 2t
Each value of t creates a distinct (x, y) ordered pair. You can think of these points as representing positions of an object, and of t as representing time in seconds. Evaluating the parametric equations for a value of t gives us the coordinates of the position of the object after t seconds have passed.