3, 9, 27, 81, 343, 729, … is a geometric sequence because each term is obtained by multiplying 3 to the preceding term.
In summary. The graph of each equation is a straight line, m is the gradient of the line and c is the y-intercept. Conversely, if a straight line has gradient m and y-intercept c it has equation y = mx + c.
<em>The right answer for:</em>
<em>cos(-170°) = _____</em>
<em>is:</em>
<em>-cos10°</em>
<h2>
Explanation:</h2>
The cosine function is an even function, which means that for every point
on the graph of
then the point
also lies on the graph of the function. In other words, we can write:

But:

So:

By property:

<h2>Learn more:</h2>
Trigonometric functions: brainly.com/question/2680050
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