We read your photo as:

Given z1 = 3 + 5i and z2 = 2 + 4i.

Mathematics

ScanSolve AI Answer

Step-by-step solution

5 steps
  1. Find z1z2\frac{z_1}{z_2}.

    Given z1=3+5iz_1 = 3 + 5i and z2=2+4iz_2 = 2 + 4i.
    To divide complex numbers, multiply the numerator and denominator by the conjugate of the denominator. The conjugate of z2=2+4iz_2 = 2 + 4i is 2−4i2 - 4i.

    z1z2=3+5i2+4i×2−4i2−4i\frac{z_1}{z_2} = \frac{3 + 5i}{2 + 4i} \times \frac{2 - 4i}{2 - 4i}

    Multiply the numerators:

    (3+5i)(2−4i)=3(2)+3(−4i)+5i(2)+5i(−4i)(3 + 5i)(2 - 4i) = 3(2) + 3(-4i) + 5i(2) + 5i(-4i) =6−12i+10i−20i2= 6 - 12i + 10i - 20i^2

    Since i2=−1i^2 = -1:

    =6−2i−20(−1)= 6 - 2i - 20(-1) =6−2i+20=26−2i= 6 - 2i + 20 = 26 - 2i

    Multiply the denominators:

    (2+4i)(2−4i)=22−(4i)2(2 + 4i)(2 - 4i) = 2^2 - (4i)^2 =4−16i2= 4 - 16i^2

    Since i2=−1i^2 = -1:

    =4−16(−1)=4+16=20= 4 - 16(-1) = 4 + 16 = 20

    Now combine the numerator and denominator:

    z1z2=26−2i20=2620−220i\frac{z_1}{z_2} = \frac{26 - 2i}{20} = \frac{26}{20} - \frac{2}{20}i z1z2=1310−110i\frac{z_1}{z_2} = \frac{13}{10} - \frac{1}{10}i
  2. Determine the modulus of z1z_1.

    Given z1=3+5iz_1 = 3 + 5i. The modulus ∣z1∣|z_1| is calculated as x2+y2\sqrt{x^2 + y^2}.

    ∣z1∣=32+52|z_1| = \sqrt{3^2 + 5^2} =9+25= \sqrt{9 + 25} =34= \sqrt{34}
  3. Determine the argument of z1z_1.

    Given z1=3+5iz_1 = 3 + 5i. The argument arg⁡(z1)\arg(z_1) is θ\theta such that tan⁡θ=yx\tan \theta = \frac{y}{x}. Since x=3x=3 and y=5y=5 are both positive, z1z_1 is in the first quadrant.

    tan⁡θ=53\tan \theta = \frac{5}{3} θ=arctan⁡(53)\theta = \arctan\left(\frac{5}{3}\right)

    In degrees:

    θ≈59.04∘\theta \approx 59.04^\circ

    In radians:

    θ≈1.03 radians\theta \approx 1.03 \text{ radians}

    The results for the complex numbers are:

    z1z2=1310−110i\boxed{\frac{z_1}{z_2} = \frac{13}{10} - \frac{1}{10}i} ∣z1∣=34\boxed{|z_1| = \sqrt{34}} arg⁡(z1)=arctan⁡(53)≈59.04∘ or 1.03 radians\boxed{\arg(z_1) = \arctan\left(\frac{5}{3}\right) \approx 59.04^\circ \text{ or } 1.03 \text{ radians}}
  4. Solve the logarithm equation log⁡43x−4log⁡43=0\log_4 3^x - 4 \log_4 3 = 0.

    Use the logarithm property log⁡bMp=plog⁡bM\log_b M^p = p \log_b M:

    xlog⁡43−4log⁡43=0x \log_4 3 - 4 \log_4 3 = 0

    Factor out log⁡43\log_4 3:

    (x−4)log⁡43=0(x - 4) \log_4 3 = 0

    Since log⁡43≠0\log_4 3 \neq 0 (because 3≠40=13 \neq 4^0 = 1), we must have:

    x−4=0x - 4 = 0 x=4x = 4

    The solution to the logarithm equation is:

    x=4\boxed{x = 4}
  5. Find sin⁡(A+B)\sin(A+B) and cos⁡(A−B)\cos(A-B).

    Given sin⁡A=45\sin A = \frac{4}{5} and cos⁡B=1213\cos B = \frac{12}{13}. Angles AA and BB are both acute, meaning they are in the first quadrant.

    First, find cos⁡A\cos A and sin⁡B\sin B.
    For angle AA:
    Since AA is acute, cos⁡A>0\cos A > 0.

    cos⁡A=1−sin⁡2A=1−(45)2\cos A = \sqrt{1 - \sin^2 A} = \sqrt{1 - \left(\frac{4}{5}\right)^2} =1−1625=25−1625=925=35= \sqrt{1 - \frac{16}{25}} = \sqrt{\frac{25 - 16}{25}} = \sqrt{\frac{9}{25}} = \frac{3}{5}

    For angle BB:
    Since BB is acute, sin⁡B>0\sin B > 0.

    sin⁡B=1−cos⁡2B=1−(1213)2\sin B = \sqrt{1 - \cos^2 B} = \sqrt{1 - \left(\frac{12}{13}\right)^2} =1−144169=169−144169=25169=513= \sqrt{1 - \frac{144}{169}} = \sqrt{\frac{169 - 144}{169}} = \sqrt{\frac{25}{169}} = \frac{5}{13}

    Now, calculate sin⁡(A+B)\sin(A+B) using the formula sin⁡(A+B)=sin⁡Acos⁡B+cos⁡Asin⁡B\sin(A+B) = \sin A \cos B + \cos A \sin B:

    sin⁡(A+B)=(45)(1213)+(35)(513)\sin(A+B) = \left(\frac{4}{5}\right)\left(\frac{12}{13}\right) + \left(\frac{3}{5}\right)\left(\frac{5}{13}\right) =4865+1565= \frac{48}{65} + \frac{15}{65} =48+1565=6365= \frac{48 + 15}{65} = \frac{63}{65}

    Finally, calculate cos⁡(A−B)\cos(A-B) using the formula cos⁡(A−B)=cos⁡Acos⁡B+sin⁡Asin⁡B\cos(A-B) = \cos A \cos B + \sin A \sin B:

    cos⁡(A−B)=(35)(1213)+(45)(513)\cos(A-B) = \left(\frac{3}{5}\right)\left(\frac{12}{13}\right) + \left(\frac{4}{5}\right)\left(\frac{5}{13}\right) =3665+2065= \frac{36}{65} + \frac{20}{65} =36+2065=5665= \frac{36 + 20}{65} = \frac{56}{65}

    The results for the trigonometric expressions are:

    sin⁡(A+B)=6365\boxed{\sin(A+B) = \frac{63}{65}} cos⁡(A−B)=5665\boxed{\cos(A-B) = \frac{56}{65}}
Was this helpful?

Still stuck on this one?

Ask a follow-up, and the answer starts from this question.

Got a different question?Ask your own question
Handwritten step-by-step solution preview

Handwritten Step-by-Step Solution

Get this as a handwritten image on WhatsApp — like a tutor wrote it for you.

Try on WhatsApp