# Tutor profile: Gabriella N.

## Questions

### Subject: Trigonometry

A $$12$$ft plank connects a point on the ground to the bed of a truck. If the plank makes a $$30$$° angle with the ground, how high is the bed of the truck off the ground?

If we think about this in terms of a trigonometric triangle, we know that we have a right triangle where the hypotenuse is $$12$$, the angle is $$30$$°, and we are trying to find the height $$(x)$$. We will be using sine to solve for $$x$$ since we know (based on SOHCAHTOA) that the height $$(x)$$ is opposite of the $$30$$° angle. To set up our equation we have $$\sin(30°) = \frac{x}{12} $$ Based on the Unit Circle we know that $$\sin(30°) =\frac12 $$ So... $$\frac12 = \frac{x}{12}$$ after cross multiplying to get $$2x = 12 $$ We solve for $$x$$ to find the height of the truck bed to be $$6$$ft off the ground.

### Subject: Geometry

Find the surface area (in inches) of a cylinder where the radius is 4in ($$ r = 4 $$) and the height is 12in ($$ h = 12$$)

Recall that the formula for the surface area (SA) of a cylinder is $$SA = 2\pi rh + 2\pi r^2 $$ Since we know that $$ r = 4 $$ and $$h = 12$$, we can plug those values into our equation to get $$ SA = 2\pi (4)(12) + 2\pi (4^2) $$ Next, we simplify our answer and end up with $$ SA = 96\pi + 32\pi = 128\pi = 402.12$$ Our final answer is that the surface area of the cylinder is approximately $$402.12$$ inches

### Subject: Algebra

Multiply the Polynomials $$ y=(x^2+4)(2x^2+6) $$

Think about this polynomial as (a+b)(c+d) The first step to solve this problem is to multiply a and c $$ x^2(2x^2) = 2x^4$$ You take this product and place it after the equal sign $$ y = 2x^4 $$ Next you multiply a(d) and add that product to the equation above $$ x^2(6) = 6x^2 $$ so now you have $$ y = 2x^4 + 6x^2 $$ In the same manner you multiply b(c) and then b(d) and add those products as well $$b(c) = 4(2x^2) = 8x^2$$ $$b(d) = 4(6) = 24$$ so you have $$y = 2x^4 + 6x^2 + 8x^2 +24$$ Finally, you combine the like numbers and end up with $$y = 2x^4 + 14x^2 +24$$

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