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Convert the left side into terms with common denominator and add (converting ##cos^2+sin^2## to ##1## along the way); simplify and refer to definition of ##sec = […]

see explanation ##color(blue)( to convert radians to degrees)## ( angle in radians) ## xx 180/pi ## example: convert ## pi/2 color(black)( radians to degrees )## angle […]

Convert 260 deg to radians Ans: ## (13pi)/9## 180 deg –> pi ##1 deg –> pi/180## ##260 deg –> ((260pi)/180) = (13pi)/9##

Use trigonometric identities and the FOIL method. We are asked to prove that ##(sin x + cos x)^2 = 1 + 2 sin(x) cos(x)##. 1) Change […]

Calculate ##arcsin (-1/sqrt2)## Ans: ##(5pi)/4 and (7pi)/4## Unit circle and trig table of special arcs –> ##sin x = – 1/sqrt2 = – sqrt2/2## –> ##arc […]

##8## Use the formula for the area of a circle: ##A=pir^2## Here the area is ##16pi##: ##16pi=pir^2## Divide both sides by ##pi##: ##16=r^2## Take the square […]

##-sqrt 7/3## Let ##a = arc cos (-3/4) in Q2## wherein tangent is also negative. Then the given expression is ##tan a = sin a/cos a=-sqrt(1-(-3/4)^2)/(-3/4)=-sqrt […]

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##240^o## has a reference angle of ##60^o## as indicated in the image below. A ##60^o## angle is a basic angle from one of the common triangles: […]