Menu Close

1-Find-the-area-of-the-triangle-formed-by-roots-of-cubic-equation-z-b-3-3-0-2-Find-product-of-all-possible-values-of-1-2-3-i-2-3-4-




Question Number 49200 by rahul 19 last updated on 04/Dec/18
1)Find the area of the triangle formed  by roots of cubic equation  (z+αb)^3 =α^3_    (α≠0).    2) Find product of all possible values  of ((1/2)+(((√3)i)/2))^(3/4)  .
1)Findtheareaofthetriangleformedbyrootsofcubicequation(z+αb)3=α3(α0).2)Findproductofallpossiblevaluesof(12+3i2)34.
Commented by rahul 19 last updated on 04/Dec/18
Ans→1) 1.3 α^2 ...  2) 1 ...
Ans1)1.3α22)1
Answered by tanmay.chaudhury50@gmail.com last updated on 04/Dec/18
2)another aporoach..  ((1/2)+((√3)/2)i)^(3/4) =(e^(i(π/3)) )^(3/4) =(e^(iπ) )^(1/4) =(cos2kπ+isin2kπ)^(1/4)   =(cos((2kπ)/4)+isin((2kπ)/4))=e^((i2kπ)/4)   so required ans is  e^(i×((2×0×π)/4)) ×e^(i((2×1×π)/4)) ×e^(i((2×−1×π)/4)) ×e^(i((2×2×π)/4))   =e^0 ×e^0 ×e^(iπ) =1×1×(cosπ+isinπ)=1
2)anotheraporoach..(12+32i)34=(eiπ3)34=(eiπ)14=(cos2kπ+isin2kπ)14=(cos2kπ4+isin2kπ4)=ei2kπ4sorequiredansisei×2×0×π4×ei2×1×π4×ei2×1×π4×ei2×2×π4=e0×e0×eiπ=1×1×(cosπ+isinπ)=1
Commented by rahul 19 last updated on 05/Dec/18
cos π =−1 , right?  So your answer comes out to be −1...  Thank you sir for providing hint i ′ve   got the correct ans. now :)
cosπ=1,right?Soyouranswercomesouttobe1Thankyousirforprovidinghintivegotthecorrectans.now:)
Commented by rahul 19 last updated on 05/Dec/18
You get   z= ( e^(iπ) )^(1/4) =(−1)^(1/4)   ⇒z^4 +1=0   ∴ Product = 1.
Yougetz=(eiπ)14=(1)14z4+1=0Product=1.
Commented by tanmay.chaudhury50@gmail.com last updated on 05/Dec/18
yes cosπ=−1 typo..
yescosπ=1typo..
Answered by tanmay.chaudhury50@gmail.com last updated on 04/Dec/18
1)(z+αb)^3 =α^3 ×1  (z+αb)^3 =α^3 ×e^(i2kπ)   z+αb=α×e^((i2kπ)/3)   z_1 +αb=α×e^((i×0×π)/3) =α(cos0^o +isin0^o )  (x_1 +iy_1 )+αb=α(1+i×0)  (x_1 ,y_1 )={(α−αb),0}←A    z_2 +αb=α×e^((i×2×1×π)/3) =α(cos120^o +isin120^o )  (x_2 +iy_2 )=−αb+α(((−1)/2)+((i×(√3))/2))  (x_2 ,y_2 )={(−αb−(α/2)),((α(√3))/2)}←B  z_3 +αb=α×e^((i×2×−1×π)/3) =α(cos120^o −isin120^o )  (x_3 +iy_3 )+αb=α(((−1)/2)−((i(√3))/2))  (x_3 ,y_3 )={(−αb−(α/2)),((−α(√3))/2)}←C  BC=α(√3)   perpendicular distance from A to BC is  α−αb+αb+(α/2)=((3α)/2)  so area ABC=(1/2)×α(√3) ×((3α)/2)=((3(√3) α^2 )/4)=1.30α^2
1)(z+αb)3=α3×1(z+αb)3=α3×ei2kπz+αb=α×ei2kπ3z1+αb=α×ei×0×π3=α(cos0o+isin0o)(x1+iy1)+αb=α(1+i×0)(x1,y1)={(ααb),0}Az2+αb=α×ei×2×1×π3=α(cos120o+isin120o)(x2+iy2)=αb+α(12+i×32)(x2,y2)={(αbα2),α32}Bz3+αb=α×ei×2×1×π3=α(cos120oisin120o)(x3+iy3)+αb=α(12i32)(x3,y3)={(αbα2),α32}CBC=α3perpendiculardistancefromAtoBCisααb+αb+α2=3α2soareaABC=12×α3×3α2=33α24=1.30α2
Commented by rahul 19 last updated on 05/Dec/18
thank you sir!���� colourful solñ!
Commented by tanmay.chaudhury50@gmail.com last updated on 05/Dec/18
your posts are unique...
yourpostsareunique

Leave a Reply

Your email address will not be published. Required fields are marked *