Take the original price and times it by .8 (you could times it by .2 and then subtract from the original price but multiplying it by .8 is much easier) 64.9x.8= 51.92 take your discounted price and multiply it by 1.085 to account for the sales tax (you multiply by 1.085 to account for the price of the item and the tax you could times it by .085 and then add it on to the price of the item but this way it shortens the amount of steps needed) 51.92x1.085= 56.3332
Round to the nearest cent
Answer=$56.33
Since there is a 5 to the right of the decimal, you will round the number immediately to the left of the decimal up. So the nearest whole number would be 71.
So base on your question the possible answer to that kind of question and the solution are the following and i hope you will understand the formula and free to ask some questions if needed.
<span>2<span>cos2</span><span>x2</span>=1+cosx=1−<span>1517</span>=<span>217</span>,<span>cos2</span><span>x2</span>=<span>117</span></span>
<span>cos<span>x2</span>=−<span>1<span>17<span>−−</span>√</span></span>....(1)</span>
<span>sin<span>x2</span>=<span>1<span>17<span>−−</span>√</span></span>,90<<span>x2</span><135</span>
<span>sin<span>x2</span>>0,cos<span>x2</span><0,tan<span>x2</span><0</span>
<span>2<span>sin2</span><span>x2</span>=1−cosx=1−<span><span>−15</span>17</span>=<span>3217</span>,sin<span>x2</span>=<span>4<span>17<span>−−</span>√</span></span>.....(2)</span><span>
divide (2) by (1) and get the value of tan x/2</span>