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How to calculate the formula of power in junior high school mathematics method?
Two ways to reduce power consumption:

The first kind:

Sin? Ten.

= (sin? x)? .

= [( 1 - cos2x)/2]? .

=( 1/8)( 1-3 cos 2 x+3 cos? 2x - cos? 2x).

= 1/8-(3/8)cos2x+(3/8)[( 1+cos4x)/2]-( 1/8)cos? 2x .

= 5/ 16-( 15/32)cos2x+(3/ 16)cos4x-( 1/32)cos6x .

The second type:

A(n) = ∫ sin? x dx .

= ∫ sin? xsinx dx .

= - ∫ sin? x d(cosx).

=-sin? xcosx + ∫ cosx? D (sin? )。

=-sin? xcosx + (n - 1)∫ cosx? Sin? x? cosx dx .

=-sin? xcosx + (n - 1)∫ sin? x? ( 1 - sin? x) dx .

=-sin? xcos x+(n- 1)A(n-2)-(n- 1)A(n).

[ 1 + (n - 1)]A(n) = - sin? xcosx + (n - 1)A(n - 2).

∴∫ Xin? x dx .

= (- 1/6)sin? xcosx + (5/6)∫ sin? x dx .

= (- 1/6)sin? xcosx + (5/6)[(- 1/4)sin? xcosx + (3/4)∫ sin? x dx].

= (- 1/6)sin? xcosx - (5/24)sin? xcos x+( 15/24)[(- 1/2)sinxcos x+( 1/2)∫dx].

= (- 1/6)sin? xcosx - (5/24)sin? xcosx-( 15/48)sinxcosx+ 15x/48+C .