Pi/4 radians
You're looking for the angle that has a secant of sqrt(2). And since the secant is simply the reciprocal of the cosine, let's take a look at that.
sqrt(2) = 1/x
x*sqrt(2) = 1
x = 1/sqrt(2)
Let's multiply both numerator and denominator by sqrt(2), so
x = sqrt(2)/2
And the value sqrt(2)/2 should be immediately obvious to you as a trig identity. Namely, that's the cosine of a 45 degree angle. Now for the issue of how to actually give you your answer. There's no need for decimals to express 45 degrees, so that caveat in the question doesn't make any sense unless you're measuring angles in radians. So let's convert 45 degrees to radians. A full circle has 360 degrees, or 2*pi radians. So:
45 * (2*pi)/360 = 90*pi/360 = pi/4
So your answer is pi/4 radians.
The total cost of the customers order is s/2 + 1.50 dollars.
<u>Explanation:</u>
Let s represent the cost of sandwich
Cost of pretzels = 1.50 dollars
Special offer by deli lunch = Half of the cost of sandwich + bag of pretxel
Cost of offer. = s/2 + 1.50 dollars
Original order = 1 sandwich
Originial cost = s dollars
45x20x18=16,200
350x9=3150
total = 19,350
Basically, you know a parallelogram has 4 angles which all add up to 360 degrees. (3x+5)+(x+3y)+2x+70=360 degrees. Just solve for x and y
