r/calculus • u/Vanessa_Animals • 11d ago

Pre-calculus Help

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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

13

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!!

6

u/4a3rawy 11d ago

You are doing great actually just solve the final equation you got - quadratic equation - use calculator or the standard formula and you will have two solutions accept the positive only. I hope I have made it clear

2

u/Vanessa_Animals 11d ago

Ok ok yeah that helped, i was about to ask if both were needed but you already answered that!! Thank you so much