# Why do we use sine?

## Why do we use sine?

The sine function is defined as the ratio of the side of the triangle opposite the angle divided by the hypotenuse. This ratio can be used to solve problems involving distance or height, or if you need to know an angle measure. Example: To find the length of the side opposite the angle, d, we use the sine function.

What are 5 things that are prohibited during the act?

Don’t bring any of these; you can’t access them:

• Textbooks, foreign language or other dictionaries, scratch paper, notes, or other aids.
• Highlighter pens, colored pens or pencils, or correction fluid/tape.
• Any electronic device, other than a permitted calculator.
• Tobacco in any form.

Can you eat during the act?

At the real ACT, you cannot eat during the test. However, you’ll be able to eat and drink outside of your testing room during the breaks.

### What calculators are not allowed on the act?

First, let’s look at which TI calculators are prohibited according to the ACT® calculator policy. Calculators with built-in or downloaded computer algebra system (CAS) functionality are not allowed, including: All model numbers that begin with TI-89 or TI-92. TI-Nspire™ CX CAS graphing calculator.

What is cos when sin is?

Looking out from a vertex with angle θ, sin(θ) is the ratio of the opposite side to the hypotenuse , while cos(θ) is the ratio of the adjacent side to the hypotenuse . No matter the size of the triangle, the values of sin(θ) and cos(θ) are the same for a given θ, as illustrated below.

Can you use programs on the act?

A: Programs must be written in the language of the calculator. Programs written in a different language, compiled, and loaded onto the calculator are not allowed. In this way, the programs can be examined on the calculator and will use calculator functions. Programs must not be lengthy.

#### Can I use calculator on Act?

Examinees may use any 4-function, scientific, or graphing calculator, as long as it is not on the prohibited list and it is modified (see below), if needed. Calculators may only be used on the mathematics test, including ACT WorkKeys Applied Math. Sharing calculators during the test is not permitted.

What is cos 2x equal to?

which allows us to replace cos2(x) in terms of the sine. In a similar manner, we can show cos(2A) = 2cos2(A) − 1….5.2 Double Angle Formulas.

Example: Find cos(2x) given that cos(x) = 0.4.
Solution: cos(2x) = 2cos2(x) − 1 = 2(0.4)2 − 1 = −0.68.

Does Sin Cos Tan?

Sin is equal to the side opposite the angle that you are conducting the functions on over the hypotenuse which is the longest side in the triangle. Cos is adjacent over hypotenuse. And tan is opposite over adjacent, which means tan is sin/cos. this can be proved with some basic algebra.

## Can I chew gum during the act?

Yes you can chew gum as long as you don’t chew loud seriously annoying when people do that. You can just spit it out during breaks. Technically, you’re not supposed to, but most proctors won’t stop you. Just don’t make it obvious or distracting.

Can you bring a water bottle to the act?

You are not allowed to eat in the test room, but you can eat outside of it during the breaks. Take your own bottle of water in case the test center does not have drinking fountains.

How long do you have to take the ACT?

3 hours and 30 minutes

### How much Trig is on the act?

There will generally be around 4-6 questions questions on the ACT that deal with trigonometry (the official ACT guidelines say that trigonometry problems make up 7% of the test).

How is sin calculated?

In a right triangle, the sine of an angle is the length of the opposite side divided by the length of the hypotenuse. In any right triangle, the sine of an angle x is the length of the opposite side (O) divided by the length of the hypotenuse (H).

Is the act in degrees or radians?

We are used to measuring and expressing angles in degrees. Some harder problems on the ACT will use radians instead of degrees. There are 2π radians in one circle. Each point on a circle corresponds to a certain number of radians.

#### Should your calculator be in radians or degrees for the SAT?

It will depend on the question. A question with angles in degrees needs the calculator to be in degrees, and a question with angles in radians needs the calculator to be in radians. Degrees are more common on the SAT than radians though.

What is cos in math?

In a right angled triangle, the cosine of an angle is: The length of the adjacent side divided by the length of the hypotenuse. The abbreviation is cos. cos(θ) = adjacent / hypotenuse.

Can you use a TI-83 on the ACT?

Although graphing capabilities are not necessary for ACT success, students accustomed to using a graphing calculator may want to find an acceptable replacement. TI-83 and TI-84 models are approved. Many schools have used these calculators in the classroom for years, so students are familiar with them.

## How long is time and a half on the act?

5 hours

What mode should my calculator be in for the act?

Eg: if you are calculating sin(30), you should be in degree mode as your angle (30) is measured in degrees. However, if you want to calculate the value of sin(pi/2), then you should be in radian mode since pi/2 is an angle in radians. When you want to graph a trig function, you should be in radian mode.

What is the formula for sin 3x?

A trigonometric identity for sin(3x) is sin(3x)=sin(x)[4cos2(x)−1] s i n ( 3 x ) = s i n ( x ) [ 4 c o s 2 ( x ) − 1 ] .

### Can you use TI-84 on ACT?

The TI-84 Plus graphing calculator is allowed during the entire portion of the math section of the ACT. You can use your TI graphing calculator to work through problems more efficiently, help verify answers, and model a difficult word problem.