Question

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Am mare nevoie de ajutor la acest exercițiu.
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Va rog, doar cine stie! ❤️​

Answer 1

Răspuns:

Explicație:

α=0°

a+b=3n+4n=7n

b+c=4n+6n=10n

a+c=3n+6n=9n
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α=30°

Aplici         formula

(x+y)²=x²+y²+2xycosα

(a+b)²=(3n)²+(4n)²+2*3n*4ncos30=

9n²+16n²+24n²*√3/2=25n²+12√3n²

(a+b)=√(25n²+12√3n²)=√n²(25+12√3)=n√(25+12√3)

(b+c)²=(4n)²+(6n)²+2*4n*6n*c0s30°=16n²+36n²+48n²*√3/2=

48n²+48n²*√3/2

b+c=√48*n²+48n²*√3/2=√48n²(1+√3/2)=4√√3(1+√3/2)

(a+c)²=(3n²)+(6n)²+2*3n*6n*cos30°=9n²+36n²+30n²*√3/2=

45n²+10n²√3

a+c=√(45n²+10n²√3)=n√45+10√3∴

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Pt   <de       45°Aplici         aceiasi        formuladar      tii        cont      ca    cos 45°=√2/2

cos60°=1/2

α=90° cos90=0

α=120 cos120= -1/2

α=150° cos150= -√3/2

α=180°  cos180= -1

α=270° cos270=0

α=360°    cos360=1