High School Math : High School Math

Study concepts, example questions & explanations for High School Math

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Example Questions

Example Question #3 : Calculus Ii — Integrals

A function is defined by the following piecewise equation:

At , the function is:

Possible Answers:

continuous

discontinuous

Correct answer:

continuous

Explanation:

The first step to determine continuity at a point is to determine if the function is defined at that point. When we substitute in 3 for , we get 18 as our -value. is thus defined for this function.

The next step is determine if the limit of the function is defined at that point. This means that the left-hand limit must be equal to the right-hand limit at . Substitution reveals the following:

Both sides of the function, therefore, approach a -value of 18.

 

Finally, we must ensure that the curve is smooth by checking the limit of the derivative of both sides.

 

Since the function passes all three tests, it is continuous.

Example Question #1 : Limits

Function

The graph depicts a function . Does  exist?

Possible Answers:

 exists because  is constant on .

 does not exist because  is undefined.

 does not exist because  is not continuous at .

 does not exist because .

 exists because .

Correct answer:

 exists because .

Explanation:

 exists if and only if ; the actual value of  is irrelevant.

As can be seen,  and ; therefore, , and   exists.

Example Question #1 : Understanding Polar Coordinates

The polar coordinates of a point are . Give its -coordinate in the rectangular coordinate system (nearest hundredth).

Possible Answers:

Correct answer:

Explanation:

Given the polar coordinates , the  -coordinate is  .  We can find this coordinate by substituting :

Example Question #2 : Understanding Polar Coordinates

The polar coordinates of a point are . Give its -coordinate in the rectangular coordinate system (nearest hundredth).

Possible Answers:

Correct answer:

Explanation:

Given the polar coordinates , the  -coordinate is  . We can find this coordinate by substituting :

Example Question #1 : Polar

The polar coordinates of a point are . Give its -coordinate in the rectangular coordinate system (nearest hundredth).

Possible Answers:

Correct answer:

Explanation:

Given the polar coordinates , the  -coordinate is  . We can find this coordinate by substituting :

Example Question #1 : Calculus Ii — Integrals

The polar coordinates of a point are . Give its -coordinate in the rectangular coordinate system (nearest hundredth).

Possible Answers:

Correct answer:

Explanation:

Given the polar coordinates , the  -coordinate is  . We can find this coordinate by substituting :

Example Question #5 : Parametric, Polar, And Vector

Find the vector where its initial point is and its terminal point is .

Possible Answers:

Correct answer:

Explanation:

We need to subtract the -coordinate and the -coordinates to solve for a vector when given its initial and terminal coordinates:

 

Initial pt:

Terminal pt:

Vector:

Vector:

Example Question #6 : Parametric, Polar, And Vector

Find the vector where its initial point is  and its terminal point is .

Possible Answers:

Correct answer:

Explanation:

 

We need to subtract the -coordinate and the -coordinate to solve for a vector when given its initial and terminal coordinates:

 

Initial pt:

Terminal pt:

Vector: 

Vector:

Example Question #1 : Vector

Let  be vectors. All of the following are defined EXCEPT:

Possible Answers:

Correct answer:

Explanation:

The cross product of two vectors (represented by "x") requires two vectors and results in another vector. By contrast, the dot product (represented by "") between two vectors requires two vectors and results in a scalar, not a vector. 

If we were to evaluate , we would first have to evaluate , which would result in a scalar, because it is a dot product.

However, once we have a scalar value, we cannot calculate a cross product with another vector, because a cross product requires two vectors. For example, we cannot find the cross product between 4 and the vector <1, 2, 3>; the cross product is only defined for two vectors, not scalars.

The answer is .

Example Question #8 : Parametric, Polar, And Vector

Find the magnitude of vector :

Possible Answers:

Correct answer:

Explanation:

To solve for the magnitude of a vector, we use the following formula:

 

 

 

 

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