Nicala's blog

ok one of the things we learned in class this week was reference angles & it was one of the easiest thing we did thats why i picked it. :-)

step 1. figure out what quadrant sin or cos is in. if you don't know what quadrant its in you won't know if the answer is negative or postive and that will throw off the answer.

step 2. subtract by 180 until you get yr answer between 0 & 90 & if you get a negative # use absolutely value to make the # postive.

{hint:if yr answer is already between 0 & 90 then you don't need to subtract.}

step 3. if yr answer is 30,45,60,or 90. then you need to use yr trig chart to figure out the exact of yr answer.

Example: Sin 225

step 1. figure out what quadrant sin 225. its in quadrant 3 which makes it negative.

{another hint: quadrant 1 0- 90 quadrant 2 91-180 quadrant 181- 270 quadrant 271- 360}

step 2. subtract by 180. 225- 180=45

step 3. next you need to find the exact value 45 on yr trig chart. 45= pi/4 on yr trig chart.