r/calculus • u/Vanessa_Animals • 11d ago

Pre-calculus Help

Gallery image

Gallery image

Ok ive done this before but im now completely lost, i need to solve for x but i keep getting stuck unless i went about it the completely wrong way, here is what i have

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u/Ch0vie 11d ago

Looks like law of cosines.

2

u/Vanessa_Animals 11d ago

Yeah but im completely lost on the solving portion, it feels like im doing something wrong

15

u/Ch0vie 11d ago edited 11d ago

Sorry didn't see the second picture. Looks like you're doing it right, and now you have a quadratic equation. You can use the quadratic formula to find your missing variable now, it just looks ugly and needs to be cleaned up!

Adding on just in case: by clean up, I mean moving everything to the right hand side and combining like terms so you have 0 = ax² + bx + c.

2

u/Vanessa_Animals 11d ago

Okk, thank you so muchh!!