Prove identity: sin2x-tanx=cos2xtanx

See below.

Step-by-step explanation:

sin2x-tanx

= 2sinx cosx - sinx/cos

=  (2sinx cos^2x - sin x) / cos x

= sinx ( 2 cos^2x - 1 ) / cos x

Now sin x / cos x = tanx  and 2 cos^2 x - 1 = cos2x

so this simplifies to cos2x tan x.

answer: y=0 if that is what u r looking for

if gloria has "carry over" minutes, (that is, any minutes paid for but not used in a month can be applied to her payment for minutes in the next month,) her total usage for the three months is: total minutes = 320 + 243 + 489 = 1052 minutes number of 200 minute blocks = 1052/200 = 5 r52 (that is 5 with a remainder of 52) rounding up the number of 200 minute blocks gives her usage for the three months as 6 blocks. the cost for six blocks is 6 x $25 = $150 she also has 200 - 52 or 148 carry over minutes if gloria pays each month and unused minutes are lost, applying the rounding up procedure to each month gives: first month usage of 320 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 second month usage of 243 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 third month usage of 489 minutes rounds up to 3 blocks of 200 minutes for a payment of 3 x $25 = $75 total payments for the three months are $50 + $50 + $75 = $175 get the plan with carry over minutes!